Highly diastereoselective synthesis of 1,3-oxazolidines under thermodynamic control using focused microwave irradiation under solvent-free conditions

Abstract

A number of 1,3-oxazolidines, derived from enantiomerically pure amino alcohols such as (−)-ephedrine and (+)-pseudoephedrine, have been synthesised under solvent-free conditions using a focused microwave reactor. The condensation reaction between the amino alcohol and an aldehyde yields 1,3-oxazolidines in excellent yields and diastereoselectivities. Prolonged microwave irradiation increases the diastereoselectivity of the reaction and produces the thermodynamically more stable diastereomer.