<i>C</i><sub>2</sub>-Symmetric Enantiopure Ethanotethered Bis(α,β-butenolides) as Templates for Asymmetric Synthesis. Application to the Synthesis of (+)-Grandisol<sup>1</sup>
作者:Pedro de March、Marta Figueredo、Josep Font、Javier Raya、Angel Alvarez-Larena、Juan F. Piniella
DOI:10.1021/jo026705w
日期:2003.3.1
Starting from D-mannitol, we have prepared several C(2)-symmetric ethanotethered bis(alpha,beta-butenolides) and studied their [2+2] photocycloaddition reaction with ethylene. The protective groups of the central diol unit have a noticeable influence on the facial selectivity of the cycloaddition, the bis(trimethylsilyloxy) derivatives showing the highest diastereoselectivity. A theoretical conformational
从D-甘露醇开始,我们准备了几个C(2)对称的乙醚双(α,β-丁烯内酯)对称并研究了它们与乙烯的[2 + 2]光环加成反应。中央二醇单元的保护基对环加成的面部选择性具有显着影响,双(三甲基甲硅烷基氧基)衍生物表现出最高的非对映选择性。基态底物的理论构象分析与实验观察到的非对面选择性非常吻合。该双(光环加合物)已被转化为对映纯环丁烷,该对映体是由乙烯与γ-羟甲基-α,β-丁烯内酯的光反应正式形成的,其中先前仅发现了中等的面部选择性。作为这些研究的应用,