catalysed by copper(i)triflate has been applied to a series of carbohydrate derivatives obtained from glucose. Dienes 1a and 1b lead to cyclobutanes 3a and 3b whereas the diastereoisomeric dienes 5a and 5b gave diastereoisomeric products 7a and 7b. These results demonstrate that the reaction is stereospecific. Products 3a and 7a were converted into bromoesters 4 and 9 respectively. The Vasella elimination
三氟甲磺酸铜催化的分子内[2 + 2]光环化已应用于一系列从
葡萄糖获得的
碳水化合物衍
生物。二烯1a和1b产生
环丁烷3a和3b,而非对映异构二烯5a和5b得到非对映异构产物7a和7b。这些结果证明该反应是立体特异性的。产物3a和7a分别转化为
溴酸酯4和9。Vasella消除8导致预期的双环醛10和环膨胀的羟基酮12。证实了对映体纯的螺环螺旋的
碳水化合物18a和18b的立体定向形成,而在实施例19中未观察到形成20和21的选择性。