Transmissive Olefination Route to Putative “Morinol I” Lignans

A series of morinol-type lignans were rapidly assembled using a Grignard-based transmissive olefination. In combination with palladium-catalyzed arylations, the strategy provides stereoselective access to (7Z,7′E), (7E,7′E), and (7E,7′Z) morinol diastereomers and the (7Z,8′E) and (7E,8′E) conjugated analogues. Critical for the E/Z stereoselectivity is a new, general method for converting alkenenitriles to alkenemethanols that circumvents the enal E/Z isomerization commonly encountered during conventional i-Bu2AlH reduction.