反应详情

To a solution of (R)-tert-butyl 1-hydroxy-4-(4-(trifluoromethyl)phenyl)butan-2-ylcarbamate (LXX) (41.3 g; 0.124 mol) in 60% aqueous acetone was added solid sodium (meta)periodate (266 g; 1.24 mol) followed by ruthenium(II) oxide hydrate (1.65 g; 12.4 mmol). The greenish suspension was stirred for 3 h before adding propan-2-ol (500 mL) and stirring for an additional 30 min. The resulting suspension was filtered through Celite, and the filtrate was concentrated under vacuum to give a brown foam. To the brown foam was added 1 N HCl to pH 1 which was followed by extraction with EtOAc. The organic layer was washed with brine and dried with MgSO4. The crude residue was then purified on a silica gel column (10:1 hexane:EtOAc) to obtain (2R)-2-[(tert-butoxycarbonyl)amino]-4-[4-(trifluoromethyl)phenyl]butanoic acid (LXXI) (18 g; 51.8 mmol, 42% yield). 1H NMR (CDCl3) δ ppm 1.46 (brs, 9H), 1.93-2.30 (m, 2H), 2.68-2.87 (m, 2H), 4.12-4.47 (m, 1H), 5.04-5.23 (m, 1H), 7.30 (d, J=8, 2H), 7.55 (d, J=8, 2H); ESIMS found for C16H20F3NO4 m/z 348.3 (M+H).

1. stirringstirring for an additional 30 min
2. filtrationThe resulting suspension was filtered through Celite
3. concentrationthe filtrate was concentrated under vacuum
4. customto give a brown foam
5. extractionwas followed by extraction with EtOAc
6. washThe organic layer was washed with brine
7. dry with materialdried with MgSO4
8. customThe crude residue was then purified on a silica gel column (10:1 hexane:EtOAc)