Electroreductive Coupling of Optically Active α,β-Unsaturated Carbonyl Compounds with Diaryl Ketones: Asymmetric Synthesis of 4,5,5-Trisubstituted γ-Butyrolactones

The electroreductive coupling of optically active N-E-crotonoyl- and N-cinnamoylimidazolidin-2-ones and oxazolidin-2-ones with diaryl ketones in the presence of chlorotrimethylsilane gave adducts with high diastereoselectivity. The adducts were readily transformed to optically active 4,5,5-trisubstituted γ-butyrolactones by treatment with TBAF.