Water → (S)-4-hydroxybutan-2-yl 2-methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenylcarbamate

HRID 245718Notes

Reaction equation

HRID 245718 reaction equation
[F-].C([N+](CCCC)(CCCC)CCCC)CCC.[CH3:19][O:20][C:21]1[CH:26]=[C:25]([B:27]2[O:31][C:30]([CH3:33])([CH3:32])[C:29]([CH3:35])([CH3:34])[O:28]2)[CH:24]=[CH:23][C:22]=1[NH:36][C:37](=[O:51])[O:38][C@H:39]([CH2:41][CH2:42][O:43][Si](C(C)(C)C)(C)C)[CH3:40].O>O1CCCC1>[CH3:19][O:20][C:21]1[CH:26]=[C:25]([B:27]2[O:31][C:30]([CH3:32])([CH3:33])[C:29]([CH3:34])([CH3:35])[O:28]2)[CH:24]=[CH:23][C:22]=1[NH:36][C:37](=[O:51])[O:38][C@H:39]([CH2:41][CH2:42][OH:43])[CH3:40]

Participants

5

Reactant 3

HCID 962WaterHCID 2724141Tetrabutylammonium FluorideHCID 67365296(S)-4-(tert-butyldimethylsilyloxy)butan-2-yl 2-methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenylcarbamate

Product 1

HCID 67364671(S)-4-hydroxybutan-2-yl 2-methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenylcarbamateYield 146.6%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To (S)-4-(tert-butyldimethylsilyloxy)butan-2-ol (1.649 mmol, 337 mg) in dichloromethane (4 ml) were added mol sieves (4A), 2-(4-isocyanato-3-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.374 mmol, 378 mg) and 4-dimethylaminopyridine (0.275 mmol, 33.6 mg) were added and the mixture was stirred at 40° C. (oil bath temperature) for 18 hours. The mol sieves were removed by filtration and the filtrate washed with water, dried (sodium sulfate) and concentrated in vacuo to give a crude product which was purified by column chromatography (silica gel, heptanes with gradient 10% to 50% of ethyl acetate) to afford (S)-4-(tert-butyldimethylsilyloxy)butan-2-yl 2-methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenylcarbamate (443 mg). Tetrabutylammonium fluoride (1M in tetrahydrofuran, 1.22 mmol, 1.22 ml) was added to (S)-4-(tert-butyldimethylsilyloxy)butan-2-yl 2-methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenylcarbamate (240 mg) in tetrahydrofuran (1 ml) at room temperature. After 20 hours water was added to the reaction mixture, extracted with dichloromethane, the organic extract dried (sodium sulfate) and concentration in vacuo to yield (S)-4-hydroxybutan-2-yl 2-methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenylcarbamate (268 mg) which was used in the next step without further purification.

Workup

  1. extractionextracted with dichloromethane
  2. extractionthe organic extract
  3. customdried
  4. concentration(sodium sulfate) and concentration in vacuo

Sources & evidence

ORD record
ord-523d38c473ea4fb2bad4a76c3d220b22
Source dataset
uspto-grants-2014_02
Patent number
US08658794B2

Reaction notes

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