摘要:
Intramolecular photo[2+2]cycloaddition of dioxidones to alkene to give eight membered lactones proceeds with complete stereo- and high regioselectivities when an ester group presents as a linking unit between the acetal carbon and the double bond of the side chain. The successful separation of some dioxinones into the enantiomers indicates the method is useful for synthesis of enantiomerically pure compounds.