Imidazole → 5(S)-(Boc-amino)-4(S)-(tert-butyldimethylsilyloxy)-6-(p-benzyloxyphenyl)-2(R)-(phenylmethyl)-hexanoic acid
Reaction equation
[C:1]([NH:8][C@@H:9]([CH2:24][C:25]1[CH:30]=[CH:29][C:28]([O:31][CH2:32][C:33]2[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=2)=[CH:27][CH:26]=1)[C@@H:10]([OH:23])[CH2:11][C@@H:12]([CH2:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)[C:13]([OH:15])=[O:14])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].[C:39]([Si:43]([CH3:46])([CH3:45])Cl)([CH3:42])([CH3:41])[CH3:40].N1C=CN=C1.C(=O)([O-])[O-].[K+].[K+]>CN(C=O)C.CO.C1COCC1.O.CCCCCC.C(OCC)(=O)C>[C:1]([NH:8][C@@H:9]([CH2:24][C:25]1[CH:26]=[CH:27][C:28]([O:31][CH2:32][C:33]2[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=2)=[CH:29][CH:30]=1)[C@@H:10]([O:23][Si:43]([C:39]([CH3:42])([CH3:41])[CH3:40])([CH3:46])[CH3:45])[CH2:11][C@@H:12]([CH2:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)[C:13]([OH:15])=[O:14])([O:3][C:4]([CH3:6])([CH3:7])[CH3:5])=[O:2]Participants
8
Reactant 4
Product 1
Reagents, catalysts & solvents 3
Procedure
Analogously to Example 1j), 1.04 g (2.00 mmol) of 5(S)-(Boc-amino)-4(S)-hydroxy-6-(p-benzyloxyphenyl)-2(R)-(phenylmethyl)-hexanoic acid in 7 ml of DMF are silylated with 1.39 g (9.0 mmol) of tert-butyldimethylchlorosilane and 1.12 g (16.4 mmol) of imidazole. Hydrolysis of the silyl ester function with 1.6 g of potassium carbonate in 46 ml of methanol/THF/water 3:1:1 and column chromatography (SiO2, hexane/ethyl acetate 4:1→2:1→1:2) of the crude product yields the title compound: TLC Rf (A)=0.69.
Sources & evidence
- ORD record
- ord-de183f502d864b5b9384f282d8523d64
- Source dataset
- uspto-grants-1997_07
- Patent number
- US05643878
Reaction notes
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