Isolation of episulfones from the Ramberg–Bäcklund rearrangement. Part 2. X-Ray molecular structure of 2,3-epithio-8,8-dimethyl-6,10- dioxaspiro[4.5]decane S,S-dioxide and of r-6-benzyl-t-7,t-8-epithio-1,4-dioxaspiro[4.4]nonane S,S-dioxide

Abstract

For the first time, episulfones have been isolated by the treatment of α-halogeno sulfones with base under the conditions of the Ramberg–Bäcklund reaction. 3,3-Dialkoxy-6-thiabicyclo[3.1.0]hexane dioxides 3a-c and 11a, b have been fully characterised, X-ray crystal structures having been obtained for compounds 3c and 11a. Attempts to prepare episulfones with substituents at the bridgehead position were unsuccessful, however. The thermal stabilities of some of these episulfones have been studied, as have their reactions with base.