Diastereoselective Cyclopropanation of Electron-Deficient Alkenes via Metal Glycal Carbenes
作者:Karl Dötz、Frank Otto
DOI:10.1055/s-2008-1067151
日期:2008.7
isopropylidene-O-protected chromium glucal and galactal carbenes have been synthesized from their glycal precursors according to the Fischer route. NMR studies indicate a preferred 5 H 4 or 4 H 5 conformation, depending on the nature of the protective group and the configuration at C-4. The complexes with glycal carbenes have been applied to the diastereoselectivecyclopropanation of methyl crotonate and
甲硅烷基-和异亚丙基-O-保护的铬葡糖醛和半乳醛卡宾已经根据Fischer路线从它们的糖前体合成。NMR研究表明优选的5 H 4 或4 H 5 构象取决于保护基团的性质和C-4的构型。与糖基卡宾的配合物已应用于巴豆酸甲酯和γ-巴豆内酯的非对映选择性环丙烷化反应。