A convenient approach to delta-amino-beta-ketoesters by vinylogous Mannich reaction of masked acetoacetates

SiCl4 is an efficient and selective catalyst for the vinylogous Mannich reaction of linear and cyclic synthetic equivalents of acetoacetate dianion, leading to delta-amino-beta-ketoesters in moderate to high yields and complete gamma-selectivity; anti-diastereoselectivity was observed by using a gamma-methyl-substituted cyclic silyloxydiene.