重氮甲烷 、
[(1R,3S,9S,11R)-3,11-Bis-carboxymethyl-7-(3,4-dimethoxy-benzoyl)-4,4,10,10-tetramethyl-8,13-dioxo-5-oxa-tricyclo[7.3.1.01,6]tridec-6-en-9-yl]-acetic acid 生成 [(1R,3S,9S,11R)-7-(3,4-Dimethoxy-benzoyl)-3,11-bis-methoxycarbonylmethyl-4,4,10,10-tetramethyl-8,13-dioxo-5-oxa-tricyclo[7.3.1.0
1,6]tridec-6-en-9-yl]-acetic acid methyl ester