Asymmetric vinylogous Michael reaction of alpha,beta-unsaturated ketones with gamma-butenolide under multifunctional catalysis

A general and direct organocatalytic asymmetric vinylogous Michael reaction of c-butenolide with alpha,beta-unsaturated ketones was investigated with a multifunctional primary amine salt as catalyst. The reaction enables straightforward access toward synthetically versatile c-substituted butenolides from simple 2(5H)-furanone with satisfactory yields, diastereo- and enantioselectivities (up to 30 : 1 dr and 95-99% ee).