Rearrangement of 5??Substituted 5??Aminopentadienals

…, D Berger, M Neuenschwander

Index: Fischer, Fabian; Berger, Daniel; Neuenschwander, Markus Angewandte Chemie - International Edition, 1998 , vol. 37, # 15 p. 2138 - 2140

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Citation Number: 4

Abstract

Abstract Strong nucleophiles are needed for inducing ring opening 3→ 4 since the pyrylium salt intermediates 3, formed from 5-X-substituted 5-aminopenta-2, 4-dienals 2 upon treatment with acid, are quite unreactive due to “aromatic” stabilization. However, this allows an easy access to a variety of 2-aminopyrylium salts 3 from “push–pull” enynes 1. X= OAc, F, Cl, Br, I, OPh.