Facial Selectivity and Stereospecificity in the (4 + 3) Cycloaddition of Epoxy Enol Silanes

The scope of the (4 + 3) cycloaddition using epoxy enol silanes has been examined. Unhindered and nucleophilic dienes react to give the highest yields, but hindered dienes give rise to higher diastereoselectivities. Notably, the cycloaddition shows facial selectivity and stereospecificity for the stereochemistry of the epoxy enol silane.