ethoxycarbonyl hexanoate 、
3,18-O-isopropylideneandrographolide 以
二氯甲烷 为溶剂,
反应 20.0h,
以60%的产率得到[(3S,4E)-4-[2-[(4aR,6aS,7R,10aS,10bR)-3,3,6a,10b-tetramethyl-8-methylidene-1,4a,5,6,7,9,10,10a-octahydronaphtho[2,1-d][1,3]dioxin-7-yl]ethylidene]-5-oxooxolan-3-yl] hexanoate