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

摘要

Using several easily accessed and inexpensive chiral auxiliaries derived from carbohydrates, all four stereoisomers of the optically active alpha,gamma-substituted gamma-butyrolactones were obtained respectively in high enantiomeric purities (up to 96% ee for trans and up to >99% ee for cis) by the SmI_2-induced reductive coupling reaction in the presence of a proton source.