L-Cysteine Catalyzed One-Pot Synthesis of Bicyclic δ-Lactones under Ball-Milling Conditions

Abstract

A series of bicyclic -lactones 4a-4t were synthesized in moderate to good yields via a simple one-pot reaction. The facile method depended on one-pot three-component reaction of aromatic aldehyde, Meldrum's acid and -diketone in the presence of L-cysteine as a catalyst under ball-milling conditions. The reactions were completed in mere 30 min in 50-87% yields. The synthesized compounds were characterized by 1 H NMR, 13 C NMR and ESI-MS.Environmental acceptability, wide substrate scope, low cost and operational simplicity are the key features of this method.