Reaction of tryptamine derivative (2b) and acetate ester (11) built up from 2-(chloromethylene)butanal (4) resulted in enamino ketone (14). Dehydration of 14 and subsequent intramolecular [4+2] cycloaddition led to 15-oxovincadifformine (15). Regio- and stereoselective reduction of the latter molecule supplied 15β-hydroxyvincadifformine (1).
色胺衍
生物 (2b) 和由 2-(
氯亚甲基)
丁醛 (4) 形成的
乙酸酯 (11) 反应生成烯胺酮 (14)。14 的脱
水和随后的分子内 [4+2] 环加成导致 15-oxovincadifformine (15)。后一种分子的区域选择性和立体选择性还原提供了 15β-羟基长春
二甲双胍 (1)。