Convenient synthesis of 2-alkynyl-cyclopropanes and -oxiranes
Abstract
Addition of nucleophiles such as dimethylsulfoxonium methylide and ButOOLi to the conjugate enyne sulfones 4–7, 11–14, 27–28 and 31 occurs at the β-position to the phenylsulfonyl group to give the corresponding cyclopropanes 15–17 and 19–22 and the oxiranes 33–38 in high yields. The thermal reactions of vinyloxirane 36 show an oxy-Cope rearrangement to give 2-phenylsulfonylphenol 39.