作者:Daniel P. Larson、Clayton H. Heathcock
DOI:10.1021/jo971413u
日期:1997.11.1
Tricolorin A (1) is a novel tetrasaccharide macrolactone that is a natural herbicide. In this paper is reported a total synthesis of 1. Coupling of hydroxy ester 18 with D-fucosyl trichloroacetimidate 23 gave fucoside 24. Removal of the C-2 pivaloyl group of 24 followed by coupling with D-glucosyl trichloroacetimidate 29 resulted in isolation of disaccharide 30. Saponification of the ester groups of
Tricolorin A(1)是一种新型四糖大内酯,是一种天然除草剂。本文报导了总合成1。将羟基酯18与D-岩藻糖基三氯乙酰亚胺酸酯23偶联得到岩藻糖苷24。除去C-2新戊酰基基团24,然后与D-葡糖基三氯乙酰胺基乙酸酯29偶联,分离出二糖30.通过Yonemitsu方案将30的酯基团皂化并随后对酸性二醇31进行选择性大内酯化仅得到所需的内酯32。组装二糖糖基三氯乙酰亚氨酸酯52的关键步骤是将L-鼠李糖苷47与L-鼠李糖基偶联。三氯乙酰亚胺酸酯43.将内酯二糖32与二糖52偶联的尝试失败。使用替代计划组装四糖,将二糖基糖基三氯乙酰亚胺酸酯58与二糖37反应,得到四糖59。再次通过Yonemitsu方案,通过对四糖酸三醇60进行选择性大内酯化生成二酯内酯63,然后将手性侧链酸添加到反应容器中。合成的三色蛋白A(1)通过对63进行脱保护得到。从岩藻糖,葡萄糖,鼠李糖和(S)-1-辛基-3-醇开