α-Sulfenyl-Directed Ring-Opening Reactions of Epoxides. 1. Highly Regio- and Stereoselective Reaction with Organo-Aluminum Reagents and Application to the Synthesis of an Aggregation Pheromone

Article abstract of DOI:10.1246/bcsj.69.2095

The reaction of 1-phenylthio-2,3-epoxyalkanes with trialkylaluminum showed definite C-2 selectivity for nucleophilic ring-opening and gave C-2 alkylated products exclusively with the complete retention of the configuration at the C-2. In contrast, upon reacting with alkenyl(dialkyl)aluminum, dialkyl(alkynyl)aluminum, or DIBAL, the nucleophilic attack occurred at the C-1 with concomitant rearrangement of the sulfenyl group to the C-2 with the complete inversion of the configuration at the C-2. The reactions of these epoxides were considered to proceed via an episulfonium ion intermediate. Upon applying the present reaction, an aggregation pheromone of African Palm Weevil was stereoselectively synthesized in short steps.