Asymmetric C-C Bond Forming Reactions by Chiral Crown Catalysts; Darzens Condensation and Nitroalkane Addition to the Double Bond

Abstract

A new, efficient crown ether 1 anellated to a sugar derivative has been prepared which shows significant asymmetric induction as phase transfer catalyst in the Michael addition of 2-nitropropane to chalcone (60% ee for the S antipode) and in the Darzens condensation of phenacyl chloride and benzaldehyde (64% ee), simultaneously changing the PT process from solid-liquid to liquid-liquid phase.