翻訳と辞書 Words near each other ・ Wallaceburg Red Devils ・ Wallacedene ・ Wallaceodendron ・ Wallaces Corner, Virginia ・ Wallacestone ・ Wallaceton (Chesapeake, Virginia) ・ Wallaceton, Pennsylvania ・ Wallacetown ・ Wallaceville ・ Wallaceville Railway Station ・ Wallace–Bolyai–Gerwien theorem ・ Wallach (crater) ・ Wallach (disambiguation) ・ Wallach brothers ・ Wallach Hall ・ Wallach rearrangement ・ Wallach v Lew Geffen Estates ・ Wallachia ・ Wallachia (disambiguation) ・ Wallachian dialect ・ Wallachian Plain ・ Wallachian Revolution of 1848 ・ Wallachian uprising (1821) ・ Wallachs (clothiers) ・ Wallacia ・ Wallacia, New South Wales ・ Wallack ・ Wallack's Theatre ・ Wallada bint al-Mustakfi ・ Wallaga Lake National Park 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 Wallach rearrangement ： ウィキペディア英語版 Wallach rearrangement The Wallach rearrangement, also named ''Wallach transformation'', is a name reaction in the organic chemistry. It is named after Otto Wallach, who discovered this reaction in 1880. In general it is a strong acid-promoted conversion of azoxybenzenes into hydroxyazobenzenes.〔Otto Wallach and E. Belli, Chem. Ber., 13, 525 (1880) 〕 ==General Reaction Scheme== The Wallach rearrangement is an organic reaction converting an aromatic azoxy compound with sulfuric acid or other strong acids to an azo compound with one arene ring substituted by a hydroxyl group in the aromatic para position.〔''Catalysis in strongly acidic media and the Wallach rearrangement'' Erwin Buncel Acc. Chem. Res.; 1975; 8(4) pp 132 – 139; 〕 Conceptually related reactions are the Fries rearrangement, the Fischer–Hepp rearrangement, the Bamberger rearrangement, the benzidine rearrangement and the Hofmann–Martius rearrangement. In the first part of the reaction, two equivalents of acid tease the oxygen atom away from the azoxy group. The resulting dicationic intermediate with an unusual R–N+=N+–R motif in this scheme has been observed by proton NMR in a system of fluoroantimonic acid and azoxybenzene at −50 °C.〔''Stable carbocations. CXXIX. Mechanism of the benzidine and Wallach rearrangements based on direct observation of dicationic reaction intermediates and related model compounds'' George A. Olah, Kenneth Dunne, David P. Kelly, Y. K. Mo J. Am. Chem. Soc.; 1972; 94(21); 7438–47.〕 In the second part, the HSO4− anion is a nucleophile in a nucleophilic aromatic substitution followed by hydrolysis. 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「Wallach 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.