Imidazole → 5(S)-(Boc-Amino)-4(S)-(tert-butyldimethylsilyloxy)-6-(p-benzyloxy-phenyl)-2(R)-[(p-benzyloxyphenyl)methyl]hexanoic acid

HRID 263781Notes

Reaction equation

HRID 263781 reaction equation
[C:1]([NH:8][C@@H:9]([CH2:32][C:33]1[CH:38]=[CH:37][C:36]([O:39][CH2:40][C:41]2[CH:46]=[CH:45][CH:44]=[CH:43][CH:42]=2)=[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:47]([Si:51]([CH3:54])([CH3:53])Cl)([CH3:50])([CH3:49])[CH3:48].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][C:36]([O:39][CH2:40][C:41]2[CH:46]=[CH:45][CH:44]=[CH:43][CH:42]=2)=[CH:37][CH:38]=1)[C@@H:10]([O:31][Si:51]([C:47]([CH3:50])([CH3:49])[CH3:48])([CH3:54])[CH3:53])[CH2:11][C@@H:12]([CH2:16][C:17]1[CH:22]=[CH:21][C:20]([O:23][CH2:24][C:25]2[CH:26]=[CH:27][CH:28]=[CH:29][CH:30]=2)=[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

HCID 795ImidazoleHCID 11430Potassium CarbonateHCID 28928tert-Butyldimethylsilyl chlorideHCID 228742795(S)-(Boc-Amino)-4(S)-hydroxy-6-(p-benzyloxyphenyl)-2(R)-[(p-benzyloxyphenyl)methyl]hexanoic acid

Product 1

HCID 156595645(S)-(Boc-Amino)-4(S)-(tert-butyldimethylsilyloxy)-6-(p-benzyloxy-phenyl)-2(R)-[(p-benzyloxyphenyl)methyl]hexanoic acid

Reagents, catalysts & solvents 3

HCID 6228DimethylformamideSolventHCID 21226206Ethyl acetate hexaneSolventHCID 21892291Methanol tetrahydrofuran waterSolvent

Procedure

Analogously to Example 1j), 2.44 g (3.90 mmol) of 5(S)-(Boc-amino)-4(S)-hydroxy-6-(p-benzyloxyphenyl)-2(R)-(p-benzyloxyphenylmethyl)-hexanoic acid in 14 ml of DMF are silylated with 2.70 g (17.6 mmol) of tert-butyldimethylchlorosilane and 2.18 g (32 mmol) of imidazole. Hydrolysis of the silyl ester function with 3.2 g of potassium carbonate in 90 ml of methanol/THF/water 3:1:1 and column chromatography (SiO2, hexane/ethyl acetate 2:1→1:1) of the crude product yields the title compound: TLC Rf (A)=0.53; FAB-MS (M+H)+ =740.

Sources & evidence

ORD record
ord-5b1fd2ea56174b2e8dbbd736c69b3ab4
Source dataset
uspto-grants-1997_07
Patent number
US05643878

Reaction notes

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