Tetrahedron

Acetal chlorination with MnO 2-trimethylchlorosilane

F Bellesia, M Boni, F Ghelfi, R Grandi, UM Pagnoni…

Index: Bellesia, Franco; Boni, Monica; Ghelfi, Franco; Grandi, Romano; Pagnoni, Ugo M.; Pinetti, Adriano Tetrahedron, 1992 , vol. 48, # 22 p. 4579 - 4586

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Citation Number: 17

Abstract

On substituting TMCS by trimethylbromosilane (TMBS) high yields of α-bromoacetals are obtained, without added salts; starting from 1,1-dimethoxyhexane, for example, yields are 94% (84% starting from hexanal), while methylester is <1%. In this case, however, the reaction must proceed through an ionic mechanism since from norbornene the MnO 2 -TMBS reagent system gives a very complex pattern of products. Molecular bromine is very likely involved ...