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Discuss on Reactions of Alcohols
Discuss on Reactions of Alcohols

... decrease in acidity is due to two factors: an increase of electron density on the oxygen atom of the more highly‐substituted alcohol, and steric hindrance (because of the alkyl groups, which inhibit solvation of the resulting alkoxide ion). Both of these situations increase the activation energy for ...
18-1 Enolates (PPT)
18-1 Enolates (PPT)

... For ordinary aldehydes and ketones, only traces of the enol form are present. The enol form is less stable by 8-12 kcal mol-1. However, for acetaldehyde, the enol form is about 100-times more stable than that of acetone because the less substituted aldehyde carbonyl is more stable than the more subs ...
Document
Document

... Results and Discussion In the course of our work, several types of chiral ligands were tested in the reaction of allylchromium complexes with benzaldehyde, but best results were obtained by ligand 1. The chiral organometallic allyl-Cr (pineno-salen) complex was prepared in situ by adding solution of ...
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... The  rate-­‐determining  step  of  the  reaction  is  the  formation  of  a  carbocation,  which  represents   the  most  stable  on  the  immediate  double  bond.    The  order  of  carbocation  stability  is  3o  >  2o  >  1o.   ...
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Lecture 14a - University of California, Los Angeles
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Lecture 13a - UCLA Chemistry and Biochemistry
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The Baylis–Hillman reaction is an organic reaction of an aldehyde
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... The Henry Reaction is a base-catalyzed C-C bond-forming reaction between nitroalkanes and aldehydes or ketones. It is similar to the Aldol Addition, and also referred to as the Nitro Aldol Reaction. If acidic protons are available (i.e. when R = H), the products tend to eliminate water to give nitr ...
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... equations to show the role of aluminium chloride as a catalyst in this reaction. Outline a mechanism for this reaction of benzene. ...
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I (21 points) Complete the following reactions by providing starting

... A. (JOC, 2008, ASAP, Loh) Chemists have been studying the Barbier-Grignard reactions with the goal of affecting the carbon-carbon bond forming reaction in solvents like water. Recent developments include the use of indium metal catalysts that react through single electron transfer mechanisms. Show t ...
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... One of these approaches consists in activating the acceptors – mostly α,β-unsaturated aldehydes (R4 = H) and ketones (R4 = alkyl) – by reversible conversion to a chiral iminium ion. As shown in Scheme 4.2a, reversible condensation of an α,β-unsaturated carbonyl compound with a chiral secondary ami ...
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... addition reaction (11.5) a reaction in which two molecules add together to form a new molecule; often involves the addition of one molecule to a double or triple bond in an unsaturated molecule. alkene (11.1) a hydrocarbon that contains one or more carbon-carbon double bonds; an unsaturated hydrocar ...
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Wolff–Kishner reduction



The Wolff–Kishner reduction is a reaction used in organic chemistry to convert carbonyl functionalities into methylene groups. In the context of complex molecule synthesis, it is most frequently employed to remove a carbonyl group after it has served its synthetic purpose of activating an intermediate in a preceding step. As such, there is no obvious retron for this reaction. Originally reported by Nikolai Kischner in 1911 and Ludwig Wolff in 1912, it has been applied to the total synthesis of scopadulcic acid B, aspidospermidine and dysidiolide.In general, the reaction mechanism first involves the in situ generation of a hydrazone by condensation of hydrazine with the ketone or aldehyde substrate. Sometimes it is however advantageous to use a pre-formed hydrazone as substrate (see modifications). The hydrazone is deprotonated by alkoxide base followed by a concerted, rate-determining step in which a diimide anion is formed. Collapse of this alkyldiimde with loss of N2 leads to formation of an alkylanion which can be protonated by solvent to give the desired product.Because the Wolff–Kishner reduction requires highly basic conditions, it is unsuitable for base-sensitive substrates. However, this method can be superior over the related Clemmensen reduction for acid-sensitive compounds such as pyrroles and for high-molecular weight compounds.
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