ethyl (4-{(1S,2R)-1-anilino-2-{[(5,5-dimethyl-2-phenyl-1,3-dioxan-2-yl)methyl]thio}-3-oxo-3-[(4S)-2-oxo-4-phenyl-1,3-oxazolidin-3-yl]propyl}phenoxy)acetate