E-commerce in Singapur Essay Example | Topics and Well Written Essays - 2750 words

E-commerce in Singapur - Essay Example In the essay "E-commerce in Singapour", the writer claims that the evolution of the Internet and powerful online technology has given way to a new area of commerce known as electronic commerce or e-commerce. E-commerce simply means doing business electronically. In other words, commercial activities are performed online such as buying and selling goods online, electronic funds transfer, and direct consumer marketing. With a large percentage of the population having access to the Internet at home and on the go, consumers are opting to shop online rather than going the conventional way to ‘brick and mortar’ shops. Today, e-commerce is proving to be a fast growing industry in Singapore with many aspiring entrepreneurs launching their business on the Internet. In order to compete with others and to increase market shares, the business organizations implement multiple technologies for shaping their core competencies and for achieving cost effectiveness. In this respect, e-com merce and e-business are two technological advancements which play very significant role in shaping modern trade. It has helped the managers in managing and controlling the challenging tasks of business activities. â€Å"According to Andersen Consulting, 80% of European top managers recognize the importance of e-commerce for their competitive edge – not only for marketing and sales but also for purchasing and procurement†. This paper will focus on the use of e-commerce and e-business in the retail industry of Singapore. ... include the importance and use of e-commerce and e-business in trade business by figuring out its multiple applications for retailing business activities. The third section will describe various issues and prospects of e-commerce and e-business for small and medium retail industry of Singapore. Finally, based on the analyses and findings from literature review, set of relevant recommendation will be offered for the retail industry of Singapore. The overall discussions and evaluation and will concentrate the on the thesis statement of this paper which is, ‘the use of e-commence and e-business will the small and medium retail industry of Singapore’. e-Commerce and e-Business in Trade and Business In the global business, the scope of e-commerce and e-business has been expanded tremendously. This has been possible due to increasing popularity and awareness regarding information technology and internet. â€Å"With developments in the Internet and Web-based technologies, dist inctions between traditional markets and the global electronics marketplace-such as business capital size, among others are gradually being narrowed down† (Kumar, 2009, p.38). These web-based information technologies are very important management tools in strategic positioning which help the business organisations to identify and grab the underlying opportunities. This is also very important for optimal utilization of human skills and other resources (Andam, 2003). In the business activities, e-commerce and e-business are very important for strategic positioning. e-Commerce and e-business are interrelated with other but there are some differences between these two from the business perspectives. Therefore, in order to better understanding, it is necessary to clarify these two terms. In the words

Contemporary Management issue (waleed) Essay Example | Topics and Well Written Essays - 2500 words

Contemporary Management issue (waleed) - Essay Example The Traditional theories of ethics look into the aspects in terms of an absolutist view. Under this regime, the theories are either claimed to be right or wrong. On the other hand, the Contemporary theories that are framed on ethics concentrates on the relativist positional views. The correctness of a given situation is determined by the Normative ethical theories (Warren, 2011). According to the views of Richard D. George, on the basis of Pluralism, the ethical theories can be conveyed in terms of two opposing patterns, Ethical Absolutism and Ethical Relativism. There are also other types of theories related to ethics, they are: Theory of Egoism Theory of Utilitarianism Theory of Egalitarianism (on basis of rights and justice) Theory of Non-Egalitarianism On the basis of the contemporary view, the ethical theories can be on: Virtue Ethics Feminist Ethics Discourse Ethics Post Modern Ethics The theories of morality and ethics are somewhat similar to each other. Some of the morality t heories are: Moral Subjectivism Cultural Relativism Ethical Egoism Devine Command Theory Kantian Theory Contractarianism The case deals with the consciousness of the U.S. government over the health hazards caused due to cigarette smoking. It claims that the Gladys Kessler (U.S. District Judge) would claim a penalty of $280 billion from the famous tobacco companies such as, Philip Morris, Liggett and Reynolds. These companies would be penalized if they are found to knowingly deceive the public regarding the addictive nature and risks associated with smoking. It was noted that about 400000 Americans die yearly due to the health issues caused from cigarettes manufactured by these companies. This paper would concentrate on an aspect that deals with the duties that the modern organizations cater to their customers. In the later stage, the essay would focus on the different theories of business ethics and morality. The theories in the course of the discussion would be related to the case study of the paper. The Duties to Customers from Companies In the contemporary world, the organizations are supposed to suffice three primary business goals. When describing about the duties of a company it is essential to shed light on the theories of business ethics. In simple terms, business ethics is often dubbed as the form of professional ethics or applied ethics which examines the ethical principles within a business environment. Moreover, it also appeals to every business aspect and is highly pertinent to the organization as well as the individuals. Business ethics encompasses both descriptive and normative dimensions. Hence, business ethics plays a crucial role in shaping the duties and activities of the consumers towards the company. Similarly, the theory of stakeholder holds high relevance in the field of business ethics. It states that a company has equal real responsibilities towards its stakeholders, but the activities differ from one group to the other. (Source: Elkin gton, 1999) As stated in the above diagram, the organizations must try to improve the state of environment, economy and society. This is as per the theory of Triple Bottom Line stated by John Elkington in 1999. This theory also states that the organization, by uplifting the societies, must try to bridge the gap between the poor and rich customers (Wright, 1995). However, catering to the social justice is the most essential factor that must be addressed by the

This Is England Essay Example | Topics and Well Written Essays - 1250 words

This Is England - Essay Example The segment of the film was between 1:31:10 and 1:34:09 in the film "This is England". We chose to analyze the segment because it builds a good platform for the art. The segment also gives the spectator of what happened in England in 1980's, as the segment shows images of various iconic signs like the rubies cube, the segment also shows the gritty elements of war people faced in Falklands and England. The violence images and anarchy combined with the archive footage of the harmless periods of the 1980's. This creates a concrete contrast and creates the feeling of viewers to continue watching to find out what happened. The segment shows images of people and event that have effects on the actors, which are revealed in the segment, and the footage reminds us the aspects: give viewers knowledge about the environment and offers the anarchic setting that is present throughout the film. The shots of the film principle character occur immediately after the titles. The connections show the re lationship between Shaun and rebellious archive footage previously in the film. The segment shows the soldier's picture by Shaun's bed and this shows enigma codes as the viewers need to know the connections. Margaret Thatcher voice is heard on the radio, which Shaun immediately turn it off: it gives the viewers the knowledge of attitudes on the prime minister at that time. Camera work. The segment has various ways of presenting "This is England", similar to what has been used in the entire film. The segment shows how the natural lighting is employed to show the realism effect. That is the way the producers used to produce "This is England". The segment is portrayed as a documentary, and the style presents things as they occur daily. Such realities are crowds, classes, and marriage. The segment does no different as documentary in concentrating on the principle character. The segment shows natural lighting consisting of light and dark. The segment shows the film at day and during the night, which makes it easy to film; because extra lighting is not required. The segment is presented in such a way that it shows the British at war and ways in which the society is united. The segment shows a hand held camera which confirms that this is a social realist art: they are low budget arts, so everything uses fewer tools and materials. Handheld camera helps the spectator to gain an insight and it involve the spectator to watch the film. At this segment, there are a variety of shots used: this makes the segment effective as the viewer is able to see all the various angles and ways of seeing something. Sounds. The soundtrack used in this segment is a diegetic sound. This type of soundtrack shows that the art is real because the spectator is able to hear the natural sounds. The sound is also used in the entire film. The producer analyzed the sound because viewers do not normally notice these sounds every day. Diegetic sound tells the visual story. Diegetic sound is another in strument to tell the story of the author. In "This is England" segment, the producer draws the viewer by shifting from the diegetic to non-diegetic. The segment changes the role of the music in the piece, he engages the viewer in the action. Also, the segment pulls off the viewer from the scene to separate the spectators from the story. The segment also uses traditional effects of sound and Foley to leverage the sounds of diegetic. The segment uses digenetic to toy with the spectators: mislead the viewers. The

Business Formation and Entrepreneurship Coursework

Business Formation and Entrepreneurship - Coursework Example Online marketing involves buying and selling of all types of products from food to spare parts to machineries and cars with only a few clicks of the mouse and online money transfer. Many people have either started companies online or shifted their physical company to operate online as well. Most people are spending much of their time on the internet and especially the social media and what this has done is expand this type of business immensely (Sheehan, 2010). The easy thing about online marketing is the convenience as well as saving of travelling and accommodation costs. An individual for example seeking to shop for the latest clothes fashion just logs into various fashion online shops and boutiques compares the prices and the quality as well as the shipping costs and time and makes the purchase. The seller is paid through a credit or debit card and the shipment is made. It is as easier as that and one can carry out transactions no matter the location whether in the office, in the car during traffic jam or even in the confines of one’s home (Leake, Vaccarello and Ginty,

Japan & successful countries Essay Example for Free

Japan successful countries Essay Japan being one of the most successful countries in the world suffered from several problems too. In order for them to achieve greatness and near perfection, they had to be broken also which made it more possible for them to stand up again and adapt to changes. For a very long time, they closed their doors to foreign countries and made life on their own without the help of anything or anyone except them alone. However, despite of this decision, Japan was able to improve their living and manage to become one of the most successful countries in the world. In present, Japan continues to adapt to the changes that the world offers them without sacrificing their own national native philosophy. Considering the success that Japan had, it is indeed amazing to know that they have imprints of foreign culture and philosophy in them. How they were able to maintain their native and national philosophy while adapting to change is something that makes them really an interesting subject to discuss. After their resistance to colonizers and isolation, they were able to foster a nation which mixes stories and culture of the west and the east. Japan and the early years after Isolation There are several amazing things that people must know and understand about Japan. When they successfully defended their country from foreign invasion in 1945, Japan freely borrowed ideas from different countries with the absence of military impositions and the presence of colonial life. They were able to adapt to changes without people telling them what to do. Instead, the country and its people freely and willingly adapted to change while isolating themselves and soon opening to the world (Kasulis). Japan philosophy Japanese philosophy is not based on their native beliefs and studies. It is rooted into several foreign philosophies which they improvised and used to give a touch of Japan in them. However despite of the fact that theirs was a mixture of several foreign ideas, there is always something that makes their philosophies their own (Kasulis). The most distinctive characteristic of Japanese philosophy is how it has assimilated and adapted foreign philosophies to its native worldview. As an isolated island nation, Japan successfully resisted foreign invasion until 1945 and, although it borrowed ideas freely throughout its history, was able to do so without the imposition of a foreign military or colonial presence. Japanese philosophy thus bears the imprint of a variety of foreign traditions, but there is always a distinctively Japanese cultural context. In order to understand the dynamics of Japanese thought, therefore, it is necessary to examine both the influence of various foreign philosophies through Japanese history and the underlying or continuing cultural orientation that set the stage for which ideas would be assimilated and in what way. Works Cited Kasulis, Thomas P. (1998). Japanese philosophy. In E. Craig (Ed. ), Routledge Encyclopedia of Philosophy. London: Routledge. Retrieved March 15, 2009, from http://www. rep. routledge. com/article/G100

Wadsworth-Emmons Cyclopropanation Reaction | Analysis

Wadsworth-Emmons Cyclopropanation Reaction | Analysis Abstract This project aims to look at the development of the Wadsworth-Emmons cyclopropanation reaction and compare it to alternative methods of cyclopropanation in order to understand why it may be used preferentially. Current applications of the WE cyclopropanation reaction are explored to see the efficacy and yield that result. Key of Abbreviations Seen below is a collection of all abbreviations used within this project and their subsequent meaning. à Ã¢â‚¬  3: Tertiary Bn: Benzyl group CCR: Corey-Chaykovsky Reagent d.e: DME: Dimethoxyethane e.e: Et: Ethyl group EWG: Electron Withdrawing Group HWE: Horner-Wadsworth-Emmons iPr: isopropyl Me: Methyl NOE: Ph: Phenyl group THF: Tetrahydrofuran WE: Wadsworth-Emmons 1: Introduction Cyclopropane  [1]  was used as an anaesthetic until it was discovered to be highly reactive and dangerous when combined with oxygen. The reactivity of cyclopropane is mainly due to the high amount of ring strain and the bond strength between the carbons being weaker than normal carbon bonds, allowing the ring to open easily. Cyclopropane structures are often found within compounds in nature (figure 1.)  [2]  that are observed to have medicinal and commercial applications, e.g. degradable insecticides such as the pyrethroid family that are less toxic to other animals in the environment  [3]  ,  [4]  . Cyclopropanation can also produce a number of hallucinogens and opoid drugs that are most widely used recreationally for there effects on human mental and visual perception, exploiting their psychedelic properties. This type of use has historically been seen within Native American tribes and ancient civilisations. Recently more research shows that they may potentially be useful in therapeutic doses in the treatment of pain, depression, alcoholism and other behavioural problems. An example of this is Codorphone, an analgesic that can be both an agonist and antagonist at ÃŽÂ ¼-opioid receptors in the body and shows a higher potency than codeine. As a result, efficient synthetic routes that produce high yields have been developed in order to produce synthetic analogues of these natural compounds, with special attention being paid to the cyclopropanation step. Over the years there have been many methods of cyclopropanation, from using zinc carbenoids (Simmons-Smith reaction  [5]  ) to stabilised ylides (Corey-Chaykovsky Reaction  [6]  ), all producing varying ratios of isomers of the product. Often, one enantiomer is the more biologically active molecule, therefore stereoselective reactions are required to obtain high yields of the desired product. The Wadsworth-Emmons cyclopropanation reaction is an example of a reaction that is selective for the generation of the trans-isomer and has advantages over other stereoselective reactions. 1.1: Chemistry of the Cyclopropane Ring Cyclopropane is the smallest of the cycloalkanes that can be formed and consists of three sp3 hybridised carbon atoms bonded to each other to form a triangular ring. Although it is the smallest cycloalkane it is also the most reactive due to the bond angle within the ring. The ideal bond angle for sp3 hybridised carbons is 109.5 ° as it at this angle that orbitals can overlap correctly and form the highest strength carbon-carbon bonds possible. As the propane ring is planar and made up of only three carbon atoms, a bond angle of 109.5 ° is not possible and is reduced to a bond angle of ~60 °. In order to achieve bond angles of 60 ° the sp3 orbitals need to form bent bonds  [8]  where their p-characteristics are increased, causing the carbon-hydrogen bond length to shorten (figure.2). It is this significant difference between the ideal bond angle and the actual bond angle exhibited that causes a high amount of ring strain. Also, the bond angle and the modified overlap of orbitals results in carbon-carbon bonds which are weaker than normal. In figure.3, as the ring size increases from cyclopropane to cyclohexane, the ring strain decreases because the ideal bond angle is reached (when in a planar conformation) and larger rings can assume a non-planar conformation. In comparison to cyclopropane, the most strained and planar ring, cyclohexane has ideal bond angles and can form both chair and boat folded conformations in order to be the least strained ring possible. Further strain in the cyclopropane ring is due to the planar conformation of the molecule, where the two hydrogens present on each carbon atom are in an eclipsed position (figure.4)2. The carbon-hydrogen bonds are locked into this high energy conformation, as the carbon-carbon bonds of the ring are unable to rotate to form a more staggered conformation and reduce torsion strain. The total strain felt by the molecule leads to the ring structure being highly unstable and is ultimately responsible for the high reactivity of cyclopropane. Due to instability, the cyclopropane ring is able to break open very easily and releases a lot of energy in the process. This ring strain causes cyclopropane to release more energy on combustion than a standard strain-free propane chain. 2: Precursors of the Wadsworth Emmons Cyclopropanation Reaction As with most reactions the Wadsworth-Emmons cyclopropanation reaction is simply a different application of an older reaction, the Horner-Wadsworth-Emmons reaction, which has the purpose of forming E- alkenes selectively. This in turn is a derivation of the original Wittig reaction first discovered in 1954 by Georg Wittig in which phosphonium ylides are used in order to form alkenes products from aldehyde or ketone reactants. 2.1: Wittig Reaction The Wittig reaction is very useful in that it will form a carbon-carbon double bond in one site specifically on the desired molecule but the stereoselectivity of the reaction is controlled by the type of phosphonium ylide used. An ylide is a species that carries a positive and a negative charge on adjacent atoms of the molecule, and in this instance it is a phosphorus atom that carries the positive charge. As seen in scheme 12, the negatively charged carbon atom of the ylide acts as a nucleophile towards the carbonyl of the ketone (electrophile) and forms a betaine species. The betaine cyclises into an oxaphosphetane ring which quickly collapses to form a very strong phosphorus-oxygen double bond and results in the production of an alkene and a triphenyl phosphine oxide. When an unstablised ylide is present in the reaction, the kinetic isomer (Z-alkene) is produced preferentially (figure. 5)2 as the intermediate oxaphosphetane ring forms irreversibly. As the stereochemistry of the substituents are locked into a syn-conformation (figure. 7), when elimination of the triphenyl phosphine oxide occurs the alkene formed has its substituents on the same side of the plane. When the negatively charged carbon is adjacent to an electron withdrawing group (EWG), in figure 6 this is represented by the ester substituent, the ylide group becomes more stable as the charge can be dispersed. This leads to the formation of the enolate resonance form and is referred to as a stabilised ylide. Unlike the unstabilised ylide, the oxaphosphetane ring that is formed is now a reversible reaction allowing interconversion between Z-orientation to E-orientation of groups in the ring before an elimination step occurs. Under the right conditions, the interconversion step can become faster than the elimination of phosphine oxide step (collapse of the ring) allowing the reaction to proceed via the thermodynamic product route. The E- isomer is the thermodynamic product as the anti- conformation (Figure.7) of the oxaphosphetane ring has the substituents on opposite sides of the molecule, reducing steric effects and producing a conformation lower in energy. The elimination of the Z-isomer is slower than that of the E-isomer, allowing the oxaphosphetane ring to open and rotation about the carbon-carbon bond to occur to form more of the E-isomer. Although the Wittig reaction works efficiently with simple carbonyl reactants, the more sterically hindered a ketone reactant is, the slower the reaction can become. This does not necessarily have a negative effect on the yield of product but will affect the suitability of the reaction in time sensitive application, e.g. the commercial industry wants a high yield of product with a moderately fast synthetic route in order to keep costs low. 2.2: Horner-Wadsworth-Emmons reaction The Horner-Wadsworth-Emmons reaction  [9]  (scheme 2.) is the preferred method to select for the E-alkenes product and instead of using phosphonium ylides (figure 6.) uses much more nucleophilic phosphonate-stabilized carbanions with an EWG attached, usually in the form of phosphonate esters. Firstly, the phosphonate ester is deprotonated using sodium hydride leading to the generation of an enolate species. This enolate/stabilised carbanion is then reacted with the chosen aldehyde or ketone to give product. As a result of its more nucleophilic nature, similar or better yields are produced and faster rates of reactions for aldehydes and ketones that are more sterically hindered are observed. The stereoselectivity of the reaction for E-alkene can be further increased by modifying the reaction conditions and the substituent groups of the phosphonate ester (figure 8.)  [10]  . The larger the alkyl groups attached to the phosphate and ester functional groups the greater the propor tion of E-isomer obtained. Using the same idea, the larger the substituent group attached to the aldehyde/ketone reagent a more improved E-selectivity is seen, for example a phenyl ring. Increasing the temperature of the reaction to room temperature (23 °C) and changing the solvent from THF to DME will also encourage E-selectivity. Figure 9 shows that the pka of the HWE reagent is lower than that of the Wittig reagent and this is due to the ester EWG on the adjacent carbon to the acidic hydrogen. The EWG helps to stabilise the carbanion that will be formed by the loss of hydrogen making the phosphonate ester a stronger acid than the phosphonium salt, whose conjugate base will be less stabilised. As seen in Scheme 2, along side the E-alkene, there is a water soluble phosphate molecule present in solution. Due to its solubility, the recovery of the pure product from the solution can be done via a simple work up and this is one of the advantages of the HWE reaction over the use of stabilised ylides where a à Ã¢â‚¬  3 phosphine oxide is formed. Through Wadsworth and Emmons investigations into the formation of alkenes such as stilbene in 19619, it was reported that the use of phosphonate carbanions was a more cost effective process that led to faster rates of reactions. It also produced very good yields in more mild conditions in comparison to stabilised phosphonium ylides. Phosphonate carbanions have a greater scope in number of different ketone and aldehyde reagents that they can successfully react with. Comparing both methods, when using stabilised ylides the resulting solution will contain a mixture of the isomers and therefore a suitable method is needed in order to separate them. Scheme 2. 2.3: Wadsworth-Emmons Cyclopropanation Similarly to the HWE reaction and keeping in mind the steric effects of large substituents, the reaction uses phosphonate-stabilised carbanions like the phosphonoacetate anion with epoxide and lactone reagents in order to form trans-cyclopropane rings within molecules. As seen in scheme 3  [12]  , the phosphonate carbanion acts as a nucleophile towards the electrophilic carbon of the epoxide resulting in the opening of the strained ring. Due to the negative charge present on the oxygen atom the phosphoryl group undergoes 1, 4 migration on to the oxygen, forming another carbanion. The carbanion can then cyclise leading to the ÃŽÂ ³-elimination of the phosphono- ÃŽÂ ³-oxyalkanoate and the closure of the cyclopropane ring. These stabilised phosphonates give a similar yield of trans-cyclopropane to reactions using phosphonium ylides but with faster reaction times and improved diastereoselectivity  [13]  . 3: Other Methods of Cyclopropanation In order to understand how effective the WE cyclopropanation reaction is and its advantages, other methods with slightly different approaches to the same problem can be looked at. 3.1: Simmons-Smith Reaction First developed in 1958, the Simmons-Smith reaction uses the chemistry of carbenes groups, producing cyclopropyl rings from the interaction between alkenes and a carbene derivative, zinc carbenoid. A standard carbene is a neutral species containing a carbon atom with only six valence electrons2 and can be inserted into à Ã†â€™-bonds and/or à Ã¢â€š ¬-bonds of other reagents. Examples of these carbenes are :CH2 and :CCl2, where the whole carbene reagent is incorporated into the final product structure. In cases using reagents like :CCl2, further steps are required to remove the halide atoms if a standard cycloproyl ring is desired. In comparison, the zinc carbenoid is a species capable of forming carbenes but does not react in exactly the same way as them. The zinc carbenoid is formed by the insertion of a zinc atom into a molecule diiodomethane using a copper catalyst, as seen below, and its mechanism of action is compared to that of a singlet carbene where the reaction is concert ed. The carbon structure (-CH2) within the zinc carbenoid is incorporated into the cyclopropyl ring whilst the resulting metal halide is released into solution. This is done via an intermediate complex formed between the alkene, carbene and metal halide so that the carbene is not released on its own. One of the advantages of this method of cyclopropanation is the ease with which the stereochemistry of the product can be controlled. As the reaction is stereospecific, in order to obtain a product with a trans-cyclopropane ring, an alkene with E- stereochemistry can be used as the original stereochemistry will be retained. The rate of reaction of this can be dramatically increased by the presence of allylic alcohols with the same stereochemistry as the alkene, as the zinc atom can coordinate with the oxygen in a transition state to add the carbene to the same face of the molecule. The example below (figure. 10)  [14]  shows that this reaction is extremely effective at producing hig h yields of trans-cyclopropane product. Scheme 4. This reaction exhibits easy control over stereoselectivity and undergoes a relatively simple mechanism, making it easy to understand why this is one of the most popular methods of cyclopropanation. A disadvantage that the WE cyclopropanation reaction does not share is that there will have to be further steps taken in order to remove the product from the solution containing the zinc halide (insoluble) whilst preventing impurities being obtained. Although in some instances the Simmons-Smith reaction has greater stereoselectivity than the WE cyclopropanation reaction with comparable yields. 3.2: Corey-Chaykovsky Reaction  [15]   This reaction uses sulphonium ylides, as opposed to the phosphonium ylides of the Wittig reaction, reacting with enones in order to form cyclopropyl structures in the molecule. Firstly there is the generation in situ of the dimethyloxosulfonium methylide, often called the Corey-Chaykovsky Reagent (CCR), from dimethyl sulfoxide and methyl iodide reacting to give a trimethyl sulfoxonium iodide salt. This salt is then deprotonated using a strong base like sodium hydride resulting in the CCR. In the mechanism of cyclopropanation, the CCR acts as a methylene transfer agent, with the carbanion acting as a nucleophile towards the alkene carbon-carbon double bond of the enone. This 1, 4 addition is followed by cyclisation within the molecule using the new carbon double bond reacting as a nucleophile toward the now electrophilic ylide carbon to form the cyclopropyl structure and a sulfonium cation (Scheme 5). In an attempt to make the reaction stereoselective more substituted sulfonium ylides with specific chirality can be used to encourage the formation of a specific enantiomer as they transfer other substituents to the enone as well as methylene (figure.)  [16]  . Scheme 5. 4: Uses of the Wadsworth-Emmons Cyclopropanation Reaction Though there are only a few specific examples of WE cyclcopropanation in action, a good idea of its efficacy can be obtained. 4.1: Synthesis of Belactosin A  [17]   (+)-Belactosin A is a naturally occurring antitumor antibacterial compound that acts as an alkylating agent in chemotherapy treatment. As an alkylating agent  [18]  it adds alkyl groups to electronegative groups such as phosphates or the amines found on guanine nucleotide bases, which are present in all cells of the body, although it is used to target mutating cancer cells. Belactosin A specifically stops the cell cycle of cancer cells at the G2/M phase, where normal DNA will have been replicated and the cell undergoes mitosis. In mutated DNA, the areas on the nucleotide bases affected by alkylation form cross bridges with other atoms on the complementary base of the opposite strand of DNA. These bridges prevent the DNA strands from separating at these specific points, stopping steps such as transcription. As a result this prevents the mutated DNA from being copied, cells from dividing into more cancer cells and halts proliferation of these cells through out the body. It affects mutated DNA cells more readily as they undergo cell cycle at a faster and uncontrolled rate and their repair mechanisms are less effective. Armstrong and Scutt reported a good yield of 63% of the cyclopropane intermediate with greater than 95%e.e. By using H1 NMR and NOE they determined that the product obtained was the trans-isomer. 4.2: Synthesis of (R,R)- 2-Methylcyclopropanecarboxylic Acid  [19]   In agriculture and veterinary practices, insecticides like Cyromazine and Pyrethrum Extract4 are formed using the WE cyclopropanation reaction in the synthesis of (+) and (-)-chrysanthemum dicarboxylic acids from anhydro sugars  [20]  . The pyrethroids are active molecules that prevent normal transmission and excitation along the nerve cells in insects by acting on sodium/potassium channels. This results in immediate death to agricultural pests such as locusts and parasitic insects such as ticks and fleas on household pets. Due to the number of nerve cells and the speed of transmission these insecticides are up to 100 times more effective on insects than humans. Consequently, Pyrethrum extract can be used pharmaceutically without detrimental effects in the treatment of worms and scabies. Using the WE cyclopropanation method to obtain the biologically active enantiomer, Brione and company obtained excellent product yields of ~85-90% with exceptional trans-selectivity (>98%). These results were obtained under the conditions of 150 °C with HexLi/MeTHF solvent. 5: Conclusion Whilst the WE cyclopropanation reaction proves itself to be a useful step in the mechanism of formation of a few interesting biologically active compounds, the fact remains that it is an underused method. This is shown in the small volume of literature that can be obtained specifically for this reaction. As with most reactions the right balance of factors and reaction conditions are needed to get the most efficiency, and excellent yields have proved that the WE cyclopropanation reaction is capable of this in the cases of (R, R)- 2-Methylcyclopropanecarboxylic Acid and Belactosin A. Perhaps one of the reasons it is overlooked as a synthetic route is the presence of better known reactions like the Simmons-Smith reaction, as there are still some small areas that are not fully known e.g the degree of specificity of the reaction. The field of chemistry is one based on the evolution of ideas and continued search for improved yields and rates of reaction, especially in a growing area such a s the synthesis of synthetic analogues of natural compounds. In the same way that the WE cyclopropanation reaction was derived from the Wittig reaction, it could provide as a good basis for future improved methods of cyclopropanation that arise from the modification of its reagents.

Procrastination Essay -- essays research papers

Procrastination Procrastination is the avoidance of doing a task that needs to be accomplished. Procrastination has a high potential for painful consequences. It may interfere with our personal or academic success. There are those of us who wait until the due date is a day away. I am not talking about making sure the money is in the bank. I am talking about putting it off because it is a tedious chore that we do not enjoy doing. Procrastination is a big problem for many, and one that can harm your career. Whether your procrastination causes you to arrive late at work or late for meetings, or keeps you from turning projects in on time, employers do not look positively upon it There are several reasons why we procrastinate. If a project is absolutely overwhelming, to the point where you don't even start it, break it down into small, specific steps. Do one or two each day. If you complete a step and are motivated to continue, fine. But if you're not, that's fine too because you have only committed to one small piece. Just don't stop before completing that piece. If there is no immediate payoff because the project is long term, build in mini-completion points. Design a reward system similar to what you do with a task you don't like. Creating instant gratification will motivate you until you reach the final destination. If you know you can handle the project but just don't know where to start, start anywhere. Just do something. Write a title on a piece of paper. Then write something else. Eventually you'll be led to where you need to go. But it takes a little bit of momentum to get the ball rolling. This doesn't mean that you'll use any of the material y ou start with. This is fine - you need a good finished product, not a good first draft. A final, common reason for procrastination is perfectionism. Be aware that there is a difference between doing something right and doing the right thing. Perfectionists can spend their time on the wrong thing, i.e. hanging and re-hanging a picture on the office wall. Looks great, but is it getting you anywhere? If the task is meaningless in the long run, it doesn't really matter if you do it perfectly. You can still do it well, just don't let it consume you. If perfectionism is keeping you from beginning a task, reevaluate whether the ... ...ntil the last minute to start a difficult task can also be used as a defense for poor performance. You can always claim that it would have been better if there was more time. (The report would have been more comprehensive if you had been given more time to do it.) It can shield you from the consequences that you expect to occur after the project is completed. For example, not accepting a high visibility special assignment will shield you from the consequences of a) being in the limelight and possibly failing or b) doing well and being offered more challenge. This could take the form of a new position as the office manager, a relocation or a new set of circumstances that may be frightening. If you are not feeling up to the rigorous standards that you have set for success, or are trying to live up to others have set that the expectations for your performance, delay can be used as a means of self-protection. When you find yourself blocked, unable to start a task and you have tried everything else, ask yourself: "Is there anything, no matter how small, that I am willing to do?" When you find that small thing, you are no longer procrastinating.