Abstract
Treatment of dimethyl 2-butynylsulfonium bromide (II) with benzaldehyde gave cis-and trans-2, 4-diphenyl-5-methyl-6-(2-phenyl-trans-1, 2-epoxyethyl)-1, 3-dioxin (III and IV), 1, 5-diphenyl-2-methyl-trans-4, 5-epoxy-trans-1-penten-3-one (V) and methyl 2-methyl-5-hydroxy-5-phenyl-2, 3-pentadienyl sulfide (VI). Dimethyl 2-propynylsulfonium bromide (VIII), however, reacted with benzaldehyde to give only one product, 1, 5-diphenyltrans-4, 5-epoxy-trans-1-penten-3-one (IX). A mechanistic assumption for the formation of these compounds from the acetylenic sulfonium bromides was given.
