A Novel Catalytic and Highly Enantioselective Approach for the Synthesis of Optically Active Carbohydrate Derivatives
作者:Hélène Audrain、Jacob Thorhauge、Rita G. Hazell、Karl Anker Jørgensen
DOI:10.1021/jo9918596
日期:2000.7.1
yield, high diastereoselectivity, and excellent enantioselectivity. The potential of the reaction is demonstrated by the synthesis of optically active carbohydrates such as spiro-carbohydrates, an ethyl beta-D-mannoside tetraacetate, and acetal-protected C-2-branched carbohydrates. On the basis of X-ray crystallographic data and the absolute configuration of the products, it is proposed that the alkene
提出了α,β-不饱和羰基化合物与手性双恶唑啉与Cu(OTf)2结合作为路易斯酸催化的富电子烯烃的催化对映选择性逆电子需求异狄尔斯-阿尔德反应。γ-取代的β,γ-不饱和α-酮酯与乙烯基醚和各种类型的顺式-二取代的烯烃的反应以良好的收率,高的非对映选择性和优异的对映选择性进行。该反应的潜力通过合成旋光碳水化合物如螺糖,β-D-甘露糖苷乙基四乙酸酯和乙缩醛保护的C-2-支链碳水化合物来证明。根据X射线晶体学数据和产物的绝对构型,建议烯烃接近反应α的si面,