ChemInform Abstract: Diels-Alder Reactions of (RS)-3-[(1S)-Isoborneol-10-sulfinyl]-1-methoxybuta-1,3-dienes with Electron-Deficient Carbodienophiles. The Effects of Lewis Acid Catalysis

Uncatalyzed cycloadditions of (RS,E)-1 and (RS,Z)-3-[(1S)-isoborneol-10-sulfinyl]-1-methoxybuta-1,3-diene 2 with maleimide and N-phenylmaleimide occurred with complete endo and very high facial diastereoselectivities. The effects of Lewis acid catalysis on these Diels–Alder reactions have been evaluated. LiClO4 catalyzed cycloaddition of 1 with dimethyl maleate gave cyclohexene 13 as the unique product with complete control of endo and π-facial diastereoselectivities exerted by the sulfinyl group. A significant improvement in diastereoselectivity was also observed in the LiClO4 catalyzed cycloaddition of 1 with dimethyl fumarate.