上游原料
4-(acetyloxy)-1,9,12,15-tetrahydroxy-10,14,17,17-tetramethyl-11-oxo-6-oxatetracyclo[11.3.1.0~3,10~.0~4,7~]heptadec-13-en-2-yl benzoate 3-{[(1,1-dimethylethyl)oxy]carbonyl}-2-[4-(methyloxy)phenyl]-4-phenyl-1,3-oxazolidine-5-carboxylic acid 4-(acetyloxy)-1,9,12,15-tetrahydroxy-10,14,17,17-tetramethyl-11-oxo-6-oxatetracyclo[11.3.1.0~3,10~.0~4,7~]heptadec-13-en-2-yl benzoate (2R,3S)-3-amino-2-hydroxy-3-phenylpropanoic acid(2R,3S)-3-((tert-butoxycarbonyl)amino)-2-hydroxy-3-phenylpropanoic acid