Iron-catalyzed regio- and stereoselective substitution of 2,4-alkadienyl carboxylates with aryl Grignard reagents

Abstract

Treatment of 2,4-alkadienyl carboxylates with an aryl Grignard reagent in the presence of a catalytic amount of FeCl2 affords diene derivatives in high yields with regio- and cis-stereoselectivity. Additionally, optically active 2,4-alkadienyl carboxylates afford the corresponding optically active dienes in high yields and with excellent degrees of chiral transfer. More importantly, the absolute structures of both starting material and product clarified the stereochemical pathway.