重氮甲烷 、
(4aS)-7,9,9-trimethyl-2-oxo-(4ar,7at,9ac)-dodecahydro-7c,11ac-methano-cyclobuta[6,7]cyclonona[1,2-b]pyran-4ξ-carboxylic acid 生成 (4a
S)-7,9,9-trimethyl-2-oxo-(4a
r,7a
t,9a
c)-dodecahydro-7
c,11a
c-methano-cyclobuta[6,7]cyclonona[1,2-
b]pyran-4ξ carboxylate methyl ester