Development of a solid-phase ‘asymmetric resin-capture–release’ process: application of an ephedrine chiral resin in an approach to γ-butyrolactones

Abstract

The potential of a solid-phase asymmetric resin-capture–release strategy for high-throughput synthesis has been evaluated. Fukuzawa's Sm(II)-mediated, asymmetric approach to γ-butyrolactones was selected to illustrate the feasibility of such a process. α,β-Unsaturated esters immobilised on an ephedrine chiral resin have been applied in an asymmetric approach to γ-butyrolactones. Lactone products are obtained in moderate isolated yields with selectivities up to 96% ee. In addition, we have shown that the ephedrine resin can be conveniently recovered and recycled although in some cases lower yields were obtained on reuse of the chiral resin. A short synthesis of a moderate DNA-binding microbial metabolite using asymmetric resin-capture–release is also described.