OUVERTURE ACIDE DE BIS-(ALKYLTHIO)-2,2 CYCLOPROPANOLS. UNE NOUVELLE METHODE D'HOMOLOGATION ET D'EXTENSION DE CYCLE

Article abstract of DOI:10.1016/0040-4020(80)80206-7

Solvolysis of 2,2-bis(alkylthio) cyclopropanols by aqueous trifluoroacetic acid occurs easily to yield conjugated α-(alkylthio)-enone and/or β-oxo-S alkylthioesters.The formation of the former most probably involves a disrotary ring opening concerted with the departure of the alkylthio group trans to hydroxyl, or, alternatively with monocyclic compounds, a 1,2-migration of the same alkylthio group synchronous with OH departure and cleavage.A nucleophilic substitution at the thioacetal centre followed by oxidative opening of the intermediate cyclopropanediol accounts for the formation of the latter.In 70percent aqueous perchloric acid the formation of enones in favoured.