Introduction of a chiral centre on C-6 of a carbohydrate unit: Application to the synthesis of the C-2 to C-15 fragment of lonomycin
作者:Deborah Anne Nicoll-Griffith、Larry Weiler
DOI:10.1016/s0040-4020(01)87081-2
日期:1991.1
add to the lactone to provide the C-6 substituted carbohydrate derivative with high stereoselectivity. This product can be converted into the dithiane 34b which when coupled with an appropriate epoxide yields compound 37 which contains the C-2 to C-15 fragment of ionomycin with the correct absolute stereochemistry at each asymmetric centre for conversion into ionomycin.
利用分子内Wadsworth-Emmons反应将葡萄糖转化为α,β-不饱和的urono-8,4-内酯29。较高级的铜酸盐加到内酯上,以提供具有高立体选择性的C-6取代的碳水化合物衍生物。该产物可以转化为二噻吩34b,当与合适的环氧化物偶联时,生成化合物37,其包含离子霉素的C-2至C-15片段,在每个不对称中心具有正确的绝对立体化学,以转化为离子霉素。