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

HRID 350487Notes

Reaction equation

HRID 350487 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) δ 1.06 (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-987a225b992b4101a7fffd1f417fc61c
Source dataset
uspto-grants-2007_02
Patent number
US07179819B2

Reaction notes

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