(4S,5R)-3-[(S)-2-(tert-butyldimethylsilyloxy)-3-{(4R,5R)-5-[(tert-butyldimethylsilyloxy)methyl]-2,2,5-trimethyl-1,3-dioxolan-4-yl}propanoyl]-4-methyl-5-phenyloxazolidin-2-one