马来酸酐 、
methyl (1S,5S,9S,10R)-16-(thiazolidin-2-yl)-15,16-epoxy-8(17),13(16),14-labdatrien-18-oate 以
氯仿 为溶剂,
反应 24.0h,
以83%的产率得到(5aSR,6SR,7SR,9aRS,9bSR)-9-[(1S,4aS,5S,8aR)-(1-methoxycarbonyl-1,4a-dimethyl-6-methylenedecahydronaphth-5-yl)ethyl]-5(5aH)-oxo-7,9a-epoxy-2,3,6,7,9a,9b-hexahydrothiazolo[2,3-a]isoindol-6-carboxylic acid