、
重氮甲烷 以
1,4-二氧六环 、
甲醇 、
乙醚 为溶剂,
以78%的产率得到methyl (2S,4aS,6aR,6aS,6bR,8aR,10S,12aS,14bR)-10-[(2R,3R,4S,5S,6S)-4,5-dihydroxy-6-[[(2S)-1-methoxy-1-oxopropan-2-yl]carbamoyl]-3-[(2R,3R,4S,5S,6S)-3,4,5-trihydroxy-6-[[(2S)-1-methoxy-1-oxopropan-2-yl]carbamoyl]oxan-2-yl]oxyoxan-2-yl]oxy-2,4a,6a,6b,9,9,12a-heptamethyl-13-oxo-3,4,5,6,6a,7,8,8a,10,11,12,14b-dodecahydro-1H-picene-2-carboxylate