Experiments with thioacetals and related substances. Part IV. Anionotropic rearrangements of gem-bisalkylthio-propenes and -butenes

Abstract

As a consequence of discrepancies in the literature, further investigations have been made concerning the identities of certain bisalkylthioalkenes and the possible existence of equilibria between the two isomers: R¹CH:CH·CH(SR²)₂⇌ R¹CH(SR²)·CH:CH·SR²(R²= Et or Buⁿ)

New attempts to prepare compounds with the first of these structures have been unsuccessful but it does appear that the above equilibrium exists when R¹= Me. We also show that inter- and intra-molecular migrations of alkylthio-groups in gem-bisalkylthio-derivatives occur with great ease, and in particular, certain of the unsaturated compounds undergo anionotropic rearrangement when they are oxidised.

Determination of structures of bisalkylthioalkenes by chemical methods cannot be relied upon and new data in connection with their proton magnetic resonance spectra have been recorded. We have also confirmed the structures of sulphur derivatives mentioned in earlier parts of this series and elsewhere.