翻訳と辞書 Words near each other ・ 2,3-Dihydroxybenzoic acid ・ 2,3-Dihydroxycinnamic acid ・ 2,3-dihydroxyindole 2,3-dioxygenase ・ 2,3-Dihydroxysuccinohydrazide ・ 2,3-diketo-5-methylthiopentyl-1-phosphate enolase ・ 2,3-Dimercapto-1-propanesulfonic acid ・ 2,3-Dimethoxy-4,5-methylenedioxyamphetamine ・ 2,3-Dimethylbutane ・ 2,3-Dimethylhexane ・ 2,3-dimethylmalate lyase ・ 2,3-Dinitrophenol ・ 2,3-Diphenylpropylamine ・ 2,3-Methylenedioxyamphetamine ・ 2,3-Oxidosqualene ・ 2,3-sigmatropic rearrangement ・ 2,3-Wittig rearrangement ・ 2,4 Dienoyl-CoA reductase ・ 2,4 Dienoyl-CoA reductase deficiency ・ 2,4'-dihydroxyacetophenone dioxygenase ・ 2,4,5-Trichlorophenoxyacetic acid ・ 2,4,5-Trihydroxyamphetamine ・ 2,4,5-Trihydroxycinnamic acid ・ 2,4,5-Trihydroxymethamphetamine ・ 2,4,5-Trimethoxyphenethylamine ・ 2,4,5-Trimethoxypropiophenone ・ 2,4,6-Tribromoanisole ・ 2,4,6-Tribromophenol ・ 2,4,6-Trichloroanisole ・ 2,4,6-Trichlorophenol ・ 2,4,6-Trihydroxyacetophenone Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク 2,3-Wittig rearrangement ： ウィキペディア英語版 2,3-Wittig rearrangement The ()-Wittig rearrangement is the transformation of an allylic ether into a homoallylic alcohol via a concerted, pericyclic process. Because the reaction is concerted, it exhibits a high degree of stereocontrol, and can be employed early in a synthetic route to establish stereochemistry. The Wittig rearrangement requires strongly basic conditions, however, as a carbanion intermediate is essential. ()-Wittig rearrangement is a competitive process. ==Introduction== ()-Sigmatropic rearrangements occur for a variety of groups X and Y (see below). When X is a carbanion and Y an alkoxide, the rearrangement is called the ()-Wittig rearrangement and the products are pent-1-en-5-ols. The ()-Wittig rearrangement, which produces isomeric pent-5-en-1-ols, is a competitive process that takes place at high temperatures. Because of the high atom economy and stereoselectivity of the ()-rearrangement, it has gained considerable synthetic utility. The carbanion is generated by direct lithiation of moderately acidic substrates, tin transmetallation, or reductive lithiation of O,S-acetals. Stereoselective methods employing chiral starting materials have been used to effect either asymmetric induction or simple diastereoselection ''(1)''File:23Gen.png 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「2,3-Wittig rearrangement」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.