First Examples of Proline‐Catalyzed Domino Knoevenagel/Hetero‐Diels–Alder/Elimination Reactions

Abstract

Abstract A novel and efficient one‐pot synthesis of lactones (pyranones) has been achieved by domino Knoevenagel/hetero‐Diels–Alder/elimination reactions of O ‐ and N ‐prenyl aldehyde derivatives with Meldrum's acid in the presence of L ‐ or D , L ‐proline. The reaction proceeds cleanly at room temperature to afford cis ‐ or trans ‐fused products in good yields with high diastereoselectivity.