A Facile Zr-Mediated Approach to (Z)-Enynols and Its Application to Regio- and Stereoselective Synthesis of Fully Substituted Dihydrofurans

Efficient synthetic approaches to stereodefined (Z)-enynols have been developed through zirconium-mediated cross-coupling reactions of three different components involving alkyne, ketone, and alkynyl bromide in a one-pot procedure. The subsequent electrophilic cyclization of a wide variety of (Z)-enynols affords fully substituted (Z)-5-(1-iodoylidene)-2,5-dihydrofurans with high regio- and stereoselectivity under mild reaction conditions.