X-Ray Analysis of Methyl Cis-1-chloro-2-trichloromethylcyclopentane-1-carboxylate

Abstract

Recently we have found that the products of 4,3-addition of trichloroacetic acid derivatives to 1,1-dichloro-4-methyl1,3-pentadiene in the presence of complex catalysts based on univalent copper undergo intramolecular cyclization, forming cyclobutanes with functional substituents [1, 2]. It was assumed that the stereoisomer composition of the isolated cyclobutanes depends on the ability of the functional group of the starting acid to be coordinated to the transition metal ion [3]. Further evidence in support of the observed tendencies was provided by cyclization of methyl 2,2,7,7-tetrachloro6-heptenate (prepared from methyl dichloroacetate and 1,1-dichloro-5-bromo-1-pentene by the procedure of [4], yield 72%) to 1-chloro-trichloromethylcyclopentane-1-carboxylic acid ester in the presence of amine complexes of univalent copper.