Dimethylformamide → 5-[[(1,1-Dimethylethyl)-diphenylsilyl]oxy]-3,4-dihydro-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acid

HRID 399162Notes

Reaction equation

HRID 399162 reaction equation
[CH3:1][C:2]([Si:5]([C:35]1[CH:40]=[CH:39][CH:38]=[CH:37][CH:36]=1)([C:29]1[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=1)[O:6][C:7]1[C:12]2[CH:13]([CH3:23])[CH:14]([CH2:19][CH2:20][CH2:21][OH:22])[C:15]([CH3:18])([CH3:17])[O:16][C:11]=2[CH:10]=[C:9]([CH2:24][CH2:25][CH2:26][CH2:27][CH3:28])[CH:8]=1)([CH3:4])[CH3:3].[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=[O:42].[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.CN(C=O)C>O>[CH3:1][C:2]([Si:5]([C:35]1[CH:36]=[CH:37][CH:38]=[CH:39][CH:40]=1)([C:29]1[CH:30]=[CH:31][CH:32]=[CH:33][CH:34]=1)[O:6][C:7]1[C:12]2[CH:13]([CH3:23])[CH:14]([CH2:19][CH2:20][C:21]([OH:42])=[O:22])[C:15]([CH3:17])([CH3:18])[O:16][C:11]=2[CH:10]=[C:9]([CH2:24][CH2:25][CH2:26][CH2:27][CH3:28])[CH:8]=1)([CH3:4])[CH3:3]

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 2724130Cornforth reagentHCID 189701315-[[(1,1-Dimethylethyl)diphenylsilyl]oxy]-3,4-dihydro-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanol

Product 1

HCID 189701375-[[(1,1-Dimethylethyl)-diphenylsilyl]oxy]-3,4-dihydro-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acidYield 48.4%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 2.2 g (3.97 mmol) of 5-[[(1,1-Dimethylethyl)diphenylsilyl]oxy]-3,4-dihydro-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanol and 7.47 g (19.86 mmol) of pyridinium dichromate (Aldrich) in anhy. DMF (Aldrich) was stirred at RT under argon for 20 hr. The reaction was diluted with water and extracted with EtOAc. The organic phase was dried and solvent removed under reduced pressure. The residue was then purified by repeated chromatography on silica gel to give 1.1 g (48%) of 5-[[(1,1-Dimethylethyl)diphenylsilyl]oxy]-3,4-dihydro-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acid as a pale yellow foam. HR EI MS: Calc M+, 572.3322; Observed, 572.3315. Ratio of 8:1 diastereoisomers as shown by 1H-NMR.

Workup

  1. extractionextracted with EtOAc
  2. customThe organic phase was dried
  3. customsolvent removed under reduced pressure
  4. customThe residue was then purified

Sources & evidence

ORD record
ord-25011d0e8ae84d01aa6c6f6be9830a04
Source dataset
uspto-grants-1998_10
Patent number
US05817766

Reaction notes

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