4-Oxazolidinecarboxylic acid, 3-[(2R)-3-(1,1-dimethylethoxy)-2-[[(9H-fluoren-9-ylmethoxy)carbonyl]amino]-1-oxopropyl]-2,2-dimethyl-, (4R)-
4-Oxazolidinecarboxylic acid, 3-[(2R)-3-(1,1-dimethylethoxy)-2-[[(9H-fluoren-9-ylmethoxy)carbonyl]amino]-1-oxopropyl]-2,2-dimethyl-, (4R)-