Synthesis of Silyloxy Dienes by Silylene Transfer to Divinyl Ketones: Application to the Asymmetric Synthesis of Substituted Cyclohexanes

Silver-catalyzed silylene transfer to divinyl ketones provided 2-silyloxy-1,3-dienes with control of stereochemistry and regioselectivity. The products participated in Diels–Alder reactions with electron-deficient alkenes and imines to form six-membered-ring products diastereoselectively. Cycloaddition reactions with alkenes bearing chiral auxiliaries provided access to chiral, nonracemic cyclohexenes. The methodology, therefore, represents a synthesis of diastereomerically and enantiomerically pure products in a single flask. The highly substituted cyclohexene products could be functionalized stereoselectively to provide cyclohexanols after oxidation of the carbon–silicon bond.