Imidazole → (S)-3,5-di-(tert-butyldimethylsilyloxy)-pentan-2-one

HRID 1700957Notes

Reaction equation

HRID 1700957 reaction equation
N1C=CN=C1.[Si:6](Cl)([C:9]([CH3:12])([CH3:11])[CH3:10])([CH3:8])[CH3:7].[Si:14]([O:21][C@H:22]1[CH2:26][CH2:25][O:24][C:23]1([OH:28])[CH3:27])([C:17]([CH3:20])([CH3:19])[CH3:18])([CH3:16])[CH3:15]>CN(C)C=O>[Si:14]([O:21][C@@H:22]([CH2:26][CH2:25][O:24][Si:6]([C:9]([CH3:12])([CH3:11])[CH3:10])([CH3:8])[CH3:7])[C:23](=[O:28])[CH3:27])([C:17]([CH3:20])([CH3:19])[CH3:18])([CH3:16])[CH3:15]

Participants

5

Reactant 3

HCID 795ImidazoleHCID 28928tert-Butyldimethylsilyl chlorideHCID 10704760(3S)-3-(tert-Butyldimethylsilyloxy)-2-hydroxy-2-methyl-tetrahydrofurane

Product 1

HCID 11782967(S)-3,5-di-(tert-butyldimethylsilyloxy)-pentan-2-oneYield 78.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

Imidazole (125 mg, 1.84 mmol, 2.2 equiv) and tert-butyl-dimethylsilyl chloride (139 mg, 0.92 mmol, 1.1 equiv) are added to a solution of (3S)-3-(tert-butyldimethylsilyloxy)-2-hydroxy-2-methyl-tetrahydrofurane 13 (194 mg, 0.83 mmol) in dimethyl formamide (800 μl). The mixture is stirred for 24 h at r.t. Purification of the reaction mixture by flash column chromatography (pentane/diethyl ether 20:1) affords (S)-3,5-di-(tert-butyidimethylsilyloxy)pentan-2-one 14 (226 mg, 78%) as a colourless oil. [α]D20=−11.8; [α]54620=−14.1 (c=1.0, CHCl3); 1H-NMR (200 MHz, CDCl3): δ(ppm)=4.16 (dd, 1H); 3.8-3.5 (m, 2H); 2.16 (s, 3H); 1.9-1.7 (m, 2H); 0.92 (s, 9H); 0.88 (s, 2H); 0.06 (s, 6H); 0.04 (s, 3H), 0.03 (s, 3H)

Workup

  1. customPurification of the reaction mixture by flash column chromatography (pentane/diethyl ether 20:1)

Sources & evidence

ORD record
ord-1a995e1ef2324338bb8184e52bad5b00
Source dataset
uspto-grants-2002_02
Patent number
US06350878B1

Reaction notes

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