11β,12α-Diacetoxy-3-(tert-butyldimethylsiloxy)-13,20-epoxy-15β-hydroxy-2,16-dioxopicras-3-en-21-oic Acid Methyl Ester 、 methyl (1R,2S,3R,6R,8R,9S,11R,14R,15R,16R,17S,18S)-16,17-diacetyloxy-11-[tert-butyl(dimethyl)silyl]oxy-3-hydroxy-9,14-dimethyl-4,12-dioxo-5,10,19-trioxahexacyclo[13.5.0.01,6.02,18.08,14.09,11]icosane-18-carboxylate 、
trans-3,4-dimethyl-2-pentenoic acid 以72%的产率得到