It was revealed by X-ray crystallography that α-unsubstituted (E)-vinyl sulfones have syn-conformation which seems to be the cause of “syn-effect” found in the conversion of (E)-vinyl sulfones to the corresponding allyl sulfones with a base under mild conditions. Syn-conformation of a terminal olefin in solid state was also confirmed.
                                    X射线晶体学显示,α-未取代(E)-
乙烯基砜具有顺式构象,这似乎是(E)-
乙烯基砜在温和条件下与碱反应转化为相应的烯丙基砜时产生“顺式效应”的原因。 固态末端烯烃的顺式构象也得到了证实。