Imidazole → 5(S)-(Boc-Amino)-4(S)-(tert-butyldimethylsilyloxy)-6-phenyl-2(R)-[(p-benzyloxylphenyl)methyl]hexanoic acid
Reaction equation
[C:1]([NH:8][C@@H:9]([CH2:32][C:33]1[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=1)[C@@H:10]([OH:31])[CH2:11][C@@H:12]([CH2:16][C:17]1[CH:22]=[CH:21][C:20]([O:23][CH2:24][C:25]2[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=2)=[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]([CH2:32][C:33]1[CH:34]=[CH:35][CH:36]=[CH:37][CH:38]=1)[C@@H:10]([O:31][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:18]=[CH:19][C:20]([O:23][CH2:24][C:25]2[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=2)=[CH:21][CH:22]=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), 1.4 g (2.69 mmol) of 5(S)-(Boc-amino)-4(S)-hydroxy-6-phenyl-2(R)-(p-benzyloxyphenylmethyl)-hexanoic acid in 2.9 ml of DMF are silylated with 1.87 g (12.4 mmol) of tert-butyldimethylchlorosilane and 1.5 g (22 mmol) of imidazole. Hydrolysis of the silyl ester function with 2.2 g of potassium carbonate in 63 ml of methanol/THF/water 3:1:1 and column chromatography (SiO2, hexane/ethyl acetate 2:1) of the crude product yields the title compound: TLC Rf (D)=0.17; tRet (II)=33.7 min; FAB-MS (M+H)+ =634.
Sources & evidence
- ORD record
- ord-e25577331ef64253bee22e544175c934
- Source dataset
- uspto-grants-1997_07
- Patent number
- US05643878
Reaction notes
Loading…