3(R)-ethyl-5(S)-[5-benzyloxy-1(S)-tert-butoxy-carbonylamino-3,3-dimethyl-pentyl]-2-oxo-tetrahydrofuran → 3-[N-Tert-butoxycarbonyl-4(S)-(3-carboxy-2,2-dimethylpropyl)-2,2-dimethyl-1,3-oxazolidin-5(S)-yl]-2(R)-ethyl-propionic acid (N-butyl)amide

Participants

Reaction Steps

Starting from 200 mg of 3(R)-ethyl-5(S)-[5-benzyloxy-1(S)-tert-butoxy- carbonylamino-3,3-dimethyl-pentyl]-2-oxo-tetrahydrofuran via 2(R)-ethyl-9-benzyloxy-5(S)-tert-butoxycarbonylamino-4(S)-hydroxy-7,7-dimethyl-nonanoic acid (N-butyl)amide (Rf (A)=0.28; FAB-MS: (M+H)+ =507), 3-[N-tert-butoxycarbonyl-4(S)-(4-benzyloxy-2,2-dimethylbutyl)-2,2-dimethyl-1,3-oxazolidin-5(S)-yl]-2(R)-ethyl-propionic acid (N-butyl)amide (Rf (B)=0.46; FAB-MS: (M+H)+ =547) and 3-[N-tert-butoxycarbonyl-4(S)-(2,2-dimethyl-4-hydroxybutyl)-2,2-dimethyl-1,3-oxazolidin-5(S)-yl]-2(R)-ethyl-propionic acid (N-butyl)amide (Rf (A)=0.24; FAB-MS: MS:(M+H)+ =457) in a manner analogous to that described in Examples 74a,74b and 74c), as the pure diastereomer: Rf (P)=0.58; FAB-MS:(M+H)+ =471.

Provenance & Evidence