A new chemoenzymatic Baylis-Hillman approach for the synthesis of enantiomerically enriched umbelactones

An efficient and convenient strategy for the enantioselective synthesis of enantiomerically enriched umbelactones is described utilizing a lipase-mediated resolution protocol, Baylis-Hillman reaction and ring closing metathesis as key steps. The lipase-resolution is carried out using several lipases from various sources in different solvents to afford the required intermediate 8 in good yield and high enantioselectivity.