A highly diastereoselective synthesis of (E)-B-2-(1-cyclopropyl-1-alkenyl)-1,3,2-dioxaborinanes. Isolation and oxidation to alkyl cyclopropyl ketones
作者:Narayan G. Bhat、Laura Garcia、Victoriano Tamez
DOI:10.1016/s0040-4039(03)01841-0
日期:2003.9
A convenient, novel synthesis of alkyl cyclopropyl ketones based on Z-1-bromo-1-alkenylboronate esters is developed. α-Bromo-(Z)-1-alkenylboronate esters readily available from literature procedures smoothly undergo a reaction with cyclopropylmagnesium bromide in tetrahydrofuran to provide the corresponding ‘ate’ complexes. These ‘ate’ complexes undergo intramolecular nucleophilic substitution reactions
开发了一种基于Z -1-溴-1-烯基硼酸酯的方便,新颖的烷基环丙基酮的合成方法。可从文献程序容易获得的α-溴-((Z)-1-烯基硼酸酯)与环丙基溴化镁在四氢呋喃中顺利进行反应,以提供相应的“配合物”配合物。这些“酸酯”配合物经过分子内亲核取代反应,以良好的分离产率(68-82%)首次提供了相应的含环丙基丙基的(E)-1-链烯基硼酸酯。这些中间体中存在的碳骨架可通过用过氧化氢和乙酸钠氧化确认,以良好的收率(72-85%)得到相应的烷基环丙基酮。