affects the E/Z ratio products of a Wittig reaction. Theory In a Wittig reaction, C=O is converted into C=C. The organophosphorus reagent or the phosphorus ylide is the nucleophile made of a positively charge phosphorus atom with three phenyl groups bonded to a negatively charge carbon atom. To form a ylide, a triphenylphosphine attacks a primary or secondary alkyl halide to form phosphonium salt which is deprotonated. To obtain the desired product in a Wittig reaction, the carbonyl compound is treated
overall objective of this experiment was to perform a Wittig reaction from creating an ylide and mixing it with a carbonyl (C=O) compound, cinnamaldehyde. The completion of the reaction was confirmed ultimately from the initial TLC analysis. Since TLC separates the components of the spotted material, as long as the retention factor values were different for cinnamaldehyde, the starting reagent, and the product(s), it was evident that some of the reaction had gone to completion. However, as seen in Figure
Wittig reactions allow the generation of an alkene from the reaction between an aldehyde/ketone and a ylide (derived from phosphonium salt).The mechanism for the synthesis of trans-9-(2-phenylethenyl) anthracene first requires the formation of the phosphonium salt by the addition of triphenylphosphine and alkyl halide. The phosphonium halide is produced through the nucleophilic substitution of 1° and 2° alkyl halides and triphenylphosphine (the nucleophile and weak base) 4 An example is benzyltriphenylphosphonium
medium was effective for the Wittig reactions involving various ylides without affecting the isomeric ratio. The improvement was more significant with aromatic and long-chain aldehydes that induced large hydrophobic effects. Consequently, water’s ability in stabilising the polar transition state and in reducing the energy of solvation through hydrophobic associations were suggested to cause the improved reaction rates and selective yields.10 In the aqueous Wittig reaction, a combination of other factors
Kristeva, Julia. About Chinese Women, trans.Anita Barrows (New York: Marion Boyars, 1986) p.16 Parker, Peter. Isherwood (2004). p.165-71, 196-8. Virginia Woolf. A Room of One’s Own (1929) (Penguin Classics, 2002) Wittig, Monique. The Straight Mind and Other Essays (Boston: Beacon Press, 1992). Wittig, Monique. Les Guérillères, trans. David Le Vay (Boston: Beacon Press, 1969) Cinema: Pabst, G. W. Die Büchse der Pandora (1929) based on Frank Wedekind’s plays Erdgeist (Earth Spirit, 1895) and Die Büchse der
Consequently, it becomes evident that Dilsey – female, the dark Other, enduring – is the pillar of strength for the Compson family, and using the theoretical perspective of Monique Wittig developing an effective critique of the Dilsey section comes to light that this chapter is the core of The Sound and The Fury. Monique Wittig, (1935 – 2003) French novelist, social theorist, poet, and professor in Women’s Studies and French at the University of... ... middle of paper ... ...man.” March 9, 2011. http://www
The Metaphorical Lesbian in Chopin’s The Awakening In “The Metaphorical Lesbian: Edna Pontellier in The Awakening” Elizabeth LeBlanc asserts that the character Edna Pontellier is an example of what Bonnie Zimmerman calls the “metaphorical lesbian.” It’s important to distinguish between Zimmerman’s concept of the “metaphorical lesbian” and lesbianism. The “metaphorical lesbian” does not have to act on lesbian feelings or even become conscious of herself as a lesbian. Instead, the “metaphorical
Tim O’Brien’s The Things They Carried portrays the struggles of soldier’s in war. The novel ultimately is a way for the author to cope with death and keep the memories of his platoon alive. Susan Wittig Albert writes: “Storytelling is healing. As we reveal ourselves in story, we become aware of the continuing core of our lives under the fragmented surface of our experience. We become aware of the multifaceted, multichaptered ' I ' who is the storyteller. We can trace out the paradoxical and even
Abstract In this experiment methyl-3-phenyl-2-propenoate was prepared using a Wittig reaction. Benzaldehyde and methyl (triphenylphosphoranylidene) acetate were used to give a final product. 0.33g of methyl3-phenyl-2-propenoate was found at the end of the experiment therefore the percentage yield of methy-3-phenyl-2-propenoate is 62%. The Rf value of benzaldehyde was found to be 0.85. The Rf value for methyl-3-phenyl-2-propenoate was found to be 0.83, the Rf values are almost the same therefore the
Dostoevsky’s Notes from Undergound - Reactions to an Overdeterministic Existence Some of the works cited are missing Dostoevsky presents his Notes from Undergound as the fragmented ramblings of an unnamed narrator. On the surface, the character’s narration appears disjointed and reaches no conclusive end ing until the author intercedes to end the book. However, a close examination of the underground man’s language reveals a progression in his collected ravings. After expressing dissatisfaction
Reactions to Patriarchal Oppression by Jane Eyre and Bertha Mason Missing Works Cited Jane Eyre and Bertha Mason are both oppressed by the British patriarchal system were men are the makers, interpreters, and enforcers of social and political rules. However, these two women differ greatly in the ways that they accept and cope with the reality of their place in society, and it is these differences that ultimately determine their fate. Jane Eyre follows the rules. Although she initially revolts
Reactions to Hooks’ Feminism is for Everybody I am not a feminist simply because I was raised in a feminist household. I am not a feminist because I am an independent, educated woman. I am not a feminist because I am a bitter female, nor because I am a “woman scorned.” I am not a feminist because I hate men, nor because I am a lesbian nor because I like to listen to the Indigo Girls. To the contrary I love men and I am not a lesbian. While I agree with hooks that “feminism is a movement to end
"We are a peculiar people," Elder Bruce R. McConkie once said (McConkie 25). The Church of Jesus Christ of Latter-day Saints is one of a few "odd" Christian religions. Many of its practices have created much persecution and political reaction, polygamy being one of these. It created much social and political persecution of the Mormons. Most of this persecution had come from anti-polygamist Christians. This is ironic because the anti-polygamists believed in the Bible, but not polygamy, one of its
Reactions to Oppression in Jamaica and South Africa "Bob Marley said How long shall they kill our prophets While we stand aside and look Little did he know that eventually The enemy will stand aside and look While we slash and kill our own brothers Knowing that already they are the victims of the situation" Lucky Dube, Victims Lucky Dube is a reggae artist from South Africa singing in a fight against oppression in his country. Like Jamaica, South Africa has been oppressed
An investigation of neutralization reactions Aim Question : What is the effect of changing the concentration of an alkali, on the volume of acid needed to neutralise it, when acid is added to it? The plan is to use two acids (Hydrochloric & Sulphuric) and one alkali (Sodium Hydroxide). The reason I need to use two acids is; because the question applies to all acids and alkalis and to just use one of each would not enable me to come to a general conclusion. If there had been more
Reactions to Industrialism in Frankenstein and The Communist Manifesto The radical changes of the nineteenth century were unlike any the world had seen before. A sense of these changes were felt by all in many aspects; not just politically, but in social and cultural means as well. When Mary Shelley's Frankenstein was published in 1831, it was clear that many general elements of the romantic era were well reflected. Similarly, Karl Marx and Frederick Engels' The Communist Manifesto appeared
Characters' Reactions to Death in Riders to the Sea In "Riders to the Sea" several reactions to the death of Michael take place when each of the individual characters learn of the tragedy and express their grief. The first, which would most naturally occur, is for someone to become extremely pessimistic. The character Mauyra most obviously becomes pessimistic even while she is still not sure of the fate of her son. Even the idea of Bartley leaving to sell the horses makes her nervous, she’s
barbier reaction: In a 50 mL round bottom flask that had a reflux condenser attachment, saturated ammonium chloride (5 mL), THF (1 mL), zinc powder (0.4 g), benzaldehyde (0.500 mL, 0.5225 g, 4.92 mmol), and allyl bromide (0.470 mL, 0.6533 g, 5.40 mmol) were charged with stir bar and stirred at room temperature for 45 minutes. Diethyl ether (10 mL) was added to the reaction mixture and stirred. The mixture was gravity filtered into a beaker that was topped with a watchglass. The filtrate was transferred
Draw the structure of the organic product for the reaction between the following compound and the phosphorus ylide shown. Solution The phosphorus ylide will only react with the carbonyl group. Final product Comment: Think of the Wittig reaction as the reverse of oxidative cleavage of alkenes. Baeyer-Viliger Oxidation The Baeyer-Viliger oxidation is an organic reaction used to convert a ketone to an ester using a peroxyacid, with an “insertion” of one oxygen atom
Use of Enthalpy Changes of Metal Reactions The problem: The problem that I will investigate is how to use enthalpy changes of metal reactions to experimentally test the reactivity series of common metals. Therefore the area that I am looking at is reactions involving metals and the heat energy that is evolved when these take place. In brief the reactivity series of metals is a list in which metals are ranked according to their reactivity, from the most reactive metals (such as Pottassium)