作者:Robert Łysek、Bartłomiej Furman、Zbigniew Kałuża、Jadwiga Frelek、Kinga Suwińska、Zofia Urbańczyk-Lipkowska、Marek Chmielewski
DOI:10.1016/s0957-4166(00)00260-3
日期:2000.8
the [2+2] cycloaddition of chlorosulfonyl isocyanate to 3-O-allenyl-α-d-xylofuranoses was investigated. It is shown that gem terminal dimethylallenes react more readily than methyl free congeners. The configuration of adducts was established by X-ray and CD-spectroscopy of alkylidene cephams. A stereochemical model of the transition state for the [2+2] cycloaddition of chlorosulfonyl isocyanate and
研究了氯磺酰基异氰酸酯[2 + 2]环加成成3 - O-烯基-α-d-木呋喃糖酶的不对称诱导的方向和大小。结果表明,与无甲基同类物相比,宝石末端的二甲基烯丙二烯更容易反应。加成物的构型通过亚烷基头孢的X射线和CD光谱确定。基于异丙苯的最低能量构象,提出了氯磺酰基异氰酸酯和烯丙基醚的[2 + 2]环加成的过渡态的立体化学模型。