Cyclisations of benzenesulfenyl chloride adducts with conjugated silyloxyenones: A new stereoselective reaction in the synthesis of 4,5-dihydrofuran-3(2H)-ones

Adducts, generated in situ from E-α′-trialkylsilyloxy-α,β-unsaturated ketones with benzenesulfenyl chloride, cyclise in the presence of dry silica or zinc bromide to produce phenylsulfanyl substituted 4,5-dihydrofuran-3(2H)-ones with high stereoselectivity; oxidative elimination of the phenylsulfanyl group completes a new route to furan-3(2H)-ones.