Androsterone-based gels enable diastereospecific reductions and diastereoselective epoxidations of gelators

Abstract

Eleven new androsterone-based gelators were synthesized, and their gelation properties and gel-mediated reactions were investigated. The relationships between the structures, gelation and self-assembly processes of the gelators are discussed. By using granular PTFE (polytetrafluoroethylene) as costirrers, quantitative and diastereospecific reductions of the gelator carbonyl groups mediated by water were achieved in the gels of seven gelators. This reduction did not occur in the control experiment which used organic solvent-mediated conventional conditions. The diastereospecific and quantitative reductions possibly occur via a hydrogen-bonded-activated carbonyl mechanism. Five of the gelators underwent gel-mediated epoxidation and the products were more diastereoselective than those obtained using conventional epoxidation reactions. This can be attributed to the ordered arrangements in the gels.