Dichloromethylenation of Lactones. 6. Efficient Synthesis of Dichloroolefins from Lactones and Acetates Using Triphenylphosphine and Tetrachloromethane
作者:Mohamed Lakhrissi、Yves Chapleur
DOI:10.1021/jo00098a039
日期:1994.9
Triphenylphosphine and tetrachloromethane react cleanly in refluxing tetrahydrofuran with substituted gamma and delta-lactones and some esters to afford the corresponding dichloroolefins in good yields. This new Wittig-type reaction provides an easy entry to this new class of compounds and tolerates a large variety of protecting groups. Application of this methodology to the dichloroolefination of simple lactones, sugar-derived lactones, and other biologically significant lactones is described.
A short route to α-chloro- and α-azido-ulosonic esters
作者:Mohammed Lakhrissi、Yves Chapleur
DOI:10.1016/s0040-4039(98)00872-7
日期:1998.6
A two step route to alpha-chloro-ulosonic esters from lactones involving the reaction of dichloroolefins with m-chloroperbenzoic acid in dichloromethane is described. Subsequent substitution of chlorine by the azide ion yields the corresponding anomeric azido-esters, which may be useful intermediates for the preparation of "anomeric amino-acids" and related compounds. (C) 1998 Elsevier Science Ltd. All rights reserved.
A convenient synthesis of substituted chiral tetrahydrofurans from sugar γ-lactones
作者:Yves Chapleur
DOI:10.1039/c39840000449
日期:——
Sugarγ-lactones react with hexamethylphosphorous triamide–tetrachloromethane to give dichloro-olefins in one step; these are then reduced to optically active tetrahydrofurans.