Double nucleophilic addition reaction to α,β-unsaturated aldimines promoted by aluminum chloride and a limited amount of water

In the presence of AlCl3 and MS 4 A containing H2O, ketene silyl acetals underwent 1,4- and then 1,2-addition with α,β-unsaturated imines to give doubly alkylated products in good yields with high diastereomeric excesses.