(4S,5S)-4-{(R)-[(4R,5S)-5-((5R,6R)-5-Benzyloxy-1-hydroxy-6-methyl-7-phenyl-hept-2-ynyl)-2,2-diethyl-[1,3]dioxolan-4-yl]-ethoxycarbonyl-trimethylsilanyloxy-methyl}-2,2-dimethyl-[1,3]dioxolane-4,5-dicarboxylic acid dimethyl ester