Iodine and Its Interhalogen Compounds: Versatile Reagents in Carbohydrate Chemistry V. Synthesis of 1,2-trans-Linked 1-Thioglycosides from the Per-O-acetylated Glycoses
作者:K. P. Ravindranathan Kartha、Robert Field
DOI:10.1080/07328309808002346
日期:1998.5.1
derivative, but the reaction is not stereospecific. Moreover, in the latter reactions a portion of the starting material remains unchanged even on prolonged reaction. With β-D-glucose pentaacetate (11) as the starting material, its epimerisation occurred during the reaction and therefore the recovered starting material was of α-D-configuration. In addition, the methyl disulphide-hexamethyldisilane system has
摘要在环境温度下用(烷基/芳硫基)三甲基硅烷和碘处理过-O-乙酰化的单糖和二糖会以非常高的收率形成相应的1,2-反式-1-硫代糖苷。在较高沸点的硫醇如乙硫醇的情况下,该反应可以在硫醇本身而不是甲硅烷基化衍生物的存在下有效地进行,但是该反应不是立体特异性的。此外,在后一反应中,即使在长时间反应下,一部分起始原料也保持不变。以β-D-葡萄糖五乙酸酯(11)为起始原料,其差向异构发生在反应过程中,因此回收的起始原料为α-D构型。此外,已经发现,甲基二硫化物-六甲基乙硅烷体系可以代替昂贵的(甲硫基)-三甲基硅烷而成为一种有效且廉价的替代品。1.致敬日本岐阜大学长谷川晃教授。2.有关第四部分,请参阅KPRK。