Fig. 4: Scope of the reaction with α,β-unsaturated aldehyde as the HB acceptor.

Reactions were performed with 30 mg of substrate 10a–p and 4 Å MS (60 mg) in the presence of catalyst 6d (20% mol) at 30 °C in 1.0 mL DCM for 60 h. Isolated yields are given; only a single stereoisomer was isolated (d.r. > 20:1); ee were measured by chiral HPLC analysis.