The 1,4-reduction of β- and γ-substituted butenolides using 5 mol% of NiCl2·6H2O and NaBH4 in MeOH for rapid access to cis-β,γ-disubstituted γ-butyrolactones is described. The reaction was selective for cis-products, which were obtained in good to excellent yields. This study showcased the influence of steric hindrance and angle strain on the diastereoselectivity outcome of conjugate reductions facilitated by in situ generated nickel-hydride.
