Carbohydrates as chiral auxiliaries in enantioselective synthesis of four stereoisomers of optically active α,γ-substituted γ-butyrolactones

Using several easily accessed and inexpensive chiral auxiliaries derived from carbohydrates, all four stereoisomers of the optically active α,γ-substituted γ-butyrolactones were obtained respectively in high enantiomeric purities (up to 96% ee for trans and up to >99% ee for cis) by the SmI2-induced reductive coupling reaction in the presence of a proton source.