Cis vicinal diols are converted to olefins using tellurides or selenide reagents. The diol is reacted to convert the hydroxyl groups into good leaving groups for nucleophilic substitution. Alkyl and aryl sulfonate groups such as mesylate or tosylate are preferred. The product is then reacted with a source of Te.sup.2- or Se.sup.2- ions, preferably an alkali metal telluride or selenide, to form the desired olefin. The process is particularly useful for generating 2',3'-unsaturation in the sugar moiety of nucleosides. Novel intermediate mesylate, tosylate and olefin derivatives of nucleosides are also provided.
顺式邻二醇可使用
碲化物或
硒化物试剂转化为烯烃。将二醇反应以将羟基转化为亲核取代的良好离去基团。烷基和芳基
磺酸酯基团,如
甲磺酸酯或对
甲苯磺酸酯,是首选的。然后,将产物与Te.sup.2-或Se.sup.2-离子源反应,最好是碱
金属
碲化物或
硒化物,形成所需的烯烃。该过程特别适用于在核苷的糖基中生成2',3'-不饱和度。还提供了新颖的
核苷中间体甲磺酸酯、对
甲苯磺酸酯和烯烃衍
生物。