Acetic Acid → (2S,4S)4-acetoxy-1-tert-butoxycarbonyl-2-tert-butyldiphenylsilyloxymethypyrrolidine

HRID 354424Notes

Reaction equation

HRID 354424 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:12][C@H:11]([OH:13])[CH2:10][C@H:9]1[CH2:14][O:15][Si:16]([C:29]([CH3:32])([CH3:31])[CH3:30])([C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[C:33](O)(=[O:35])[CH3:34].C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.CC(OC(/N=N/C(OC(C)C)=O)=O)C>C1COCC1>[C:33]([O:13][C@@H:11]1[CH2:12][N:8]([C:6]([O:5][C:1]([CH3:4])([CH3:2])[CH3:3])=[O:7])[C@H:9]([CH2:14][O:15][Si:16]([C:29]([CH3:32])([CH3:31])[CH3:30])([C:23]2[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=2)[C:17]2[CH:18]=[CH:19][CH:20]=[CH:21][CH:22]=2)[CH2:10]1)(=[O:35])[CH3:34]

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 11776TriphenylphosphineHCID 5363146Diisopropyl azodicarboxylateHCID 69332404HCID 69332404, compound

Product 1

HCID 69340895(2S,4S)4-acetoxy-1-tert-butoxycarbonyl-2-tert-butyldiphenylsilyloxymethypyrrolidineYield 99%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
50 °C

Procedure

To a stirred mixture of (2S,4R)-1-tert-butoxycarbonyl-2-tert-butyldiphenylsilyloxymethy-4-hydroxypyrrolidine (21.7 g, 47.6 mmol), acetic acid (3.0 ml, 52.4 mmol) and PPh3 (12.5 g, 52.4 mmol) in THF (330 ml) was added DIAD (9.4 ml, 47.6 mmol) at room temperature under an atmosphere of nitrogen. After 2 h stirring the same temperature, the mixture was heated at 50° C. for 2 h. After cooling to room temperature, the reaction mixture was concentrated in vacuo. The resulting residue was chromatographed on silica gel [1 Kg, n-hexane/EtOAc(5/1)], to give (2S,4S)-4-acetoxy-1-tert-butoxycarbonyl-2-tert-butyldiphenylsilyloxymethypyrrolidine (23.3 g, 99%) as a colorless oil. 1H-NMR (CDCl3) δ1.06 (s, 9H), 1.35 and 1.43 (s, 9H, amide isomers), 1.92 (br, 3H), 2.20-2.45 (m, 2H), 3.31-4.07 (m, 5H), 5.17-5.30 (m, 1H), 7.36-7.44 (m, 6H), 7.65-7.71 (m, 4H).

Workup

  1. temperatureAfter cooling to room temperature
  2. concentrationthe reaction mixture was concentrated in vacuo
  3. customThe resulting residue was chromatographed on silica gel [1 Kg, n-hexane/EtOAc(5/1)]

Sources & evidence

ORD record
ord-4b0502227edc41429caacd4a6cb4b4a7
Source dataset
uspto-grants-2004_06
Patent number
US06756378B2

Reaction notes

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