Regio- and stereoselective behavior of l-arabinal-derived vinyl epoxide in nucleophilic addition reactions. Comparison with conformationally restricted d-galactal-derived analogs
作者:Valeria Di Bussolo、Ileana Frau、Lucilla Favero、Gloria Uccello-Barretta、Federica Balzano、Paolo Crotti
DOI:10.1016/j.tet.2015.06.057
日期:2015.9
The regio- and stereoselectivity of the addition reactions of O-, C-, N-, and S-nucleophiles to l-arabinal-derived vinyl epoxide 2, the simplest non-conformationally restricted glycal-derived vinyl epoxide, has been examined and compared with the corresponding, conformationally restricted d-galactal-derived analogs 1β and 1β-Me. Results indicated that the 1,4-/1,2-regioselectivity ratio and the related
研究和比较了O-,C-,N-和S-亲核试剂与1-阿拉伯糖衍生的乙烯基环氧化物2(最简单的非构象受限的糖衍生的乙烯基环氧化物)的加成反应的区域和立体选择性带有相应的,构象受限的d-半乳糖衍生类似物1β和1β-Me。结果表明,1,4- / 1,2-区域选择性比和相关的syn-1,4- /抗1,2-立体选择性 在糖基乙烯基环氧乙烷中观察到的结构与六元不饱和环上取代基的存在以及构象自由的存在无关:它仅取决于亲核试剂与环氧乙烷氧形成配位形式的配位过程的能力。氢键或通过配位阳离子。