(5S,6R,7R)-5-Hydroxy-2-[(4S,5S)-5-((R)-1-methoxy-butyl)-2,2-dimethyl-[1,3]dioxolan-4-yl]-2,6-dimethyl-7-triethylsilanyloxy-nonan-3-one 生成 (4R,5S,6S)-4-Ethyl-6-{3-[(4S,5S)-5-((R)-1-methoxy-butyl)-2,2-dimethyl-[1,3]dioxolan-4-yl]-3-methyl-2-oxo-butyl}-5-methyl-[1,3]dioxan-2-one