[2S-[2R*[(R*),α(S*),β(S*)]]]-1-[(1,1-Dimethylethoxy)carbonyl]-β-methoxy-α-methyl-2-pyrrolidinepropanoic acid 2-hydroxy-1,2,2-triphenylethyl ester

ethyl (2R,3R,4S)-3-(N-tert-butoxycarbonyl-2'-pyrrolidinyl)-3-methoxy-2-methyl-propanoate

methyl (2R,3R,2'S)-3-(N-tert-butoxycarbonyl-2'-pyrrolidinyl)-3-methoxy-2-methylpropanoate

(S)-tert-butyl 2-((1R,2S)-1-hydroxy-2-methyl-3-oxo-3-((S)-1,2,2-triphenylethoxy)propyl)pyrrolidine-1-carboxylate

(S)-tert-butyl 2-((1R,2S)-1-methoxy-2-methyl-3-oxo-3-((S)-1,2,2-triphenylethoxy)propyl)pyrrolidine-1-carboxylate