A Synthesis of Densely Functionalized 2,3-Dihydropyrans Using Ring-Closing Metathesis and Base-Induced Rearrangements of Dihydropyran Oxides
作者:Bernd Schmidt、Holger Wildemann
DOI:10.1002/1099-0690(200009)2000:18<3145::aid-ejoc3145>3.0.co;2-b
日期:2000.9
presence of lithium dialkylamides to functionalized 2,3-dihydropyrans or 2,3-dihydrofurans, respectively, is described. The regiochemical outcome of the reaction can be influenced by the relative configuration of the starting epoxides and the steric demand of the base. The 2,3-dihydropyrans obtained were converted stereoselectively to difunctionalized 3,4-dihydropyrans by the carbon-Ferrier reaction, or to
描述了二氢吡喃和二氢呋喃氧化物的制备以及它们在二烷基氨基锂存在下的重排分别为官能化的 2,3-二氢吡喃或 2,3-二氢呋喃。反应的区域化学结果会受到起始环氧化物的相对构型和碱的空间需求的影响。获得的 2,3-二氢吡喃通过碳-费里耶反应立体选择性地转化为双官能化的 3,4-二氢吡喃,或通过添加二甲酮(由硝酸铈铵介导)转化为稠合的缩醛。立体化学结果通过机械建议合理化。