Reaction of R2R′SnCH2Li(R = R′= Me or Bu) with 1,2 : 5,6-di-O-isopropylidene-α-D-ribohexofuranos-3-ulose provides 1,2 : 5,6-di-O-isopropylidene-3-C-(R2R′Sn)methyl-α-D-allofuranose (5): the glucose isomer was not obtained. Despite a hydroxy group being in a β- position to tin in compound (5), no β-elimination products are obtained on reaction with CF3CO2H, reaction proceeding instead at the C(5)–C(6)
的R反应2 R'SnCH 2李(R = R'= Me或丁基)与1,2:5,6-二- ö异亚丙基α- d - ribohexofuranos -3-酮糖提供1,2:5, 6-二- ö异亚丙基-3- ç - (R 2 R'Sn)甲基α- d -allofuranose(5):在没有获得异构体
葡萄糖。尽管化合物(5)中的羟基位于
锡的β位,但与CF 3 CO 2 H反应时未获得β消除产物,而是在C(5)–C(6)保护基上进行了反应。在(5
碘)在β-羟基的亲核协助下被
碘化。CDCl 3中的(5 ; R = Me,R'= I)的1 H Nmr光谱表明,由于Sn OH相互作用,形成了四元螯合环。确定了(5; R = Bu,R′= I)的晶体结构。关于
锡,I和O轴向存在扭曲的三角双锥体排列;Sn-O 2.68(2)Å。