摘要:
By conversion of methyl 15,16-epoxy-20-oxo-8(17),13(16),14 labdatrien-19-oate (3) into 15,16-epoxy-8(17),13(16),14-labdatrien-19,20-olide (1) and 15,16-epoxy-8(17),13(16),14-labdatrien-20,19-olide (8), the structure of potamogetonin was proved to be 15,16-epoxy-8(17),13(16),14-ent-labdatrien-20,19-olide (10), not 1 as proposed by Smith et al.