Chiral homoenolate anion equivalents: synthesis of optically pure 5-substituted furan-2(5H)-ones

Abstract

Addition of the dianion of (+)-(R)-3-[(4-methylphenyl)sulphinyl]propionic acid (1) to aldehydes affords two main diastereoisomeric β-sulphinyl-γ-lactones, pyrolysis of which gives the two enantiomers of 5-substituted furan-2(5H)-ones in optically pure form.