Stereoselective Synthesis of Polysubstituted 2,5-Dihydrofurans from Reaction of 1,4-Dilithio-1,3-dienes with Aldehydes

Abstract

[reaction: see text] Reaction of 1,4-dilithio-1,3-diene derivatives with 2 equiv of aldehydes affords polysubstituted 2,5-dihydrofurans in good to high yields with perfect regio- and stereoselectivities. Hexa-2,4-diene-1,6-dialcoholates are proposed as the first intermediates, which undergo a cyclization and subsequent elimination of Li(2)O to generate the 2,5-dihydrofuran derivatives.