Stereoselective synthesis of 3a,7a-dihydro-3H,4H-furo[3,4-c]pyran-1-ones via intramolecular hetero-Diels–Alder reaction
作者:Cyril Fuhrer、Roland Messer、Robert Häner
DOI:10.1016/j.tetlet.2004.04.006
日期:2004.5
The synthesis of 3a,7a-dihydro-3H,4H-furo[3,4-c]pyran-1-ones via an intramolecular hetero-Diels–Alder reaction of easily accessible α,β-unsaturated γ-ketoesters was investigated. The reaction was found to proceed in a highly stereoselective way leading to single, cis-configured product isomers. The same diastereomer is formed, independently of the configuration of the enone double bond of the precursor
研究了通过容易获得的α,β-不饱和γ-酮酸酯的分子内杂狄尔斯-阿尔德反应合成3a,7a-dihydro-3 H,4 H-呋喃[3,4- c ]吡喃-1-酮。发现该反应以高度立体选择性的方式进行,从而产生单一的,顺式构型的产物异构体。形成相同的非对映异构体,而与前体的烯酮双键的构型无关。各个E-和Z-异构体通过内-E-syn或exo-Z-syn过渡态反应。