[(1R,2S,3R,4S,7R,9S,10S,12R,15S)-4,12-Diacetyloxy-1,9,15-trihydroxy-10,14,17,17-tetramethyl-11-oxo-6-oxatetracyclo[11.3.1.03,10.04,7]heptadec-13-en-2-yl] benzoate 生成 [(1R,2S,3R,4S,7R,9S,10S,12R,15S)-4,12-diacetyloxy-1,15-dihydroxy-10,14,17,17-tetramethyl-11-oxo-9-triethylsilyloxy-6-oxatetracyclo[11.3.1.03,10.04,7]heptadec-13-en-2-yl] benzoate