Synthesis of 2,3-anhydro- and 3,4-anhydro-hexopyranosides having a methyl branch on the oxirane ring, and their reactions with some lithium methylcuprate reagents
作者:Juji Yoshimura、Nobuya Kawauchi、Toshio Yasumori、Ken-ichi Sato、Hironobu Hashimoto
DOI:10.1016/0008-6215(84)85203-9
日期:1984.10
synthesized. The reactions of these, together with those of a known 3-C-methyl epoxide (2), with three kinds of lithium methylcuprate were investigated. Except for 2 and 7, the vicinal monodeoxy di-C-methyl derivatives were obtained by attack of the cuprates at the sterically less-hindered site of the oxirane ring, irrespective of the stereoelectronic effect. Formation of a unique, acyclic 1-enitol derivative
新增了三个具有2-C-甲基或3-C-甲基分支的2,3-脱水醛-吡喃二吡喃糖苷以及三个具有3-C-甲基(7)或4-C-甲基分支的3,4-脱水醛-吡喃二吡喃糖苷合成的。研究了它们与已知的3-C-甲基环氧化物(2)与三种甲基铜锂的反应。除2和7外,通过在环氧乙烷环的空间较少受阻的位点处的铜酸盐的攻击,获得邻位的单脱氧二-C-甲基衍生物,而与立体电子效应无关。确定了由2形成的独特的无环1-烯醇衍生物和由7形成的4-烯醇酮衍生物。还观察到了铜酸盐之间反应性的差异。