Total synthesis of two novel 5,6,7,8-tetrahydroindolizine alkaloids, polygonatines A and B
作者:Andrew Dinsmore、Karen Mandy、Joseph P. Michael
DOI:10.1039/b517573a
日期:——
polygonatines A and B, two simple but structurally novel alkaloids, have been substantiated by synthesis. Cyclisation of 4-(1H-pyrrol-1-yl)butanoic acid or its ethyl ester produced 6,7-dihydroindolizin-8(5H)-one , formylation of which at C-3 followed by reduction afforded polygonatine A . Acetylation of this alkaloid followed by displacement of the acetate with ethanol yielded polygonatine B , possibly via