Direct anti glycolate aldol reaction of protected chiral N-hydroxyacetyl thiazolidinethiones with acetals catalyzed by a nickel(II) complex

Abstract

The direct and stereocontrolled addition of (S)‐4‐isopropyl‐N‐(2‐pivaloyloxyacetyl)‐1,3‐thiazolidine‐2‐thione to dialkyl acetals of aromatic and α,β‐unsaturated aldehydes catalyzed by 2.5-5 mol‐% of a nickel(II) complex permits the synthesis of diastereomerically pure and fully protected anti aldol adducts in good to high yields. The catalytic species is formed in situ from commercially available and easy to handle (Me3P)2NiCl2, which makes this reaction a direct, catalytic, and experimentally simple approach to the asymmetric anti glycolate aldol reaction.