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

HRID 399161Notes

Reaction equation

HRID 399161 reaction equation
[OH:1][C:2]1[C:7]2[CH:8]([CH3:18])[CH:9]([CH2:14][CH2:15][CH2:16][OH:17])[C:10]([CH3:13])([CH3:12])[O:11][C:6]=2[CH:5]=[C:4]([CH2:19][CH2:20][CH2:21][CH2:22][CH3:23])[CH:3]=1.CN(C=O)C.[H-].[Na+].[C:31]([Si:35](Cl)([C:42]1[CH:47]=[CH:46][CH:45]=[CH:44][CH:43]=1)[C:36]1[CH:41]=[CH:40][CH:39]=[CH:38][CH:37]=1)([CH3:34])([CH3:33])[CH3:32]>CCOC(C)=O>[CH3:34][C:31]([Si:35]([C:42]1[CH:47]=[CH:46][CH:45]=[CH:44][CH:43]=1)([C:36]1[CH:37]=[CH:38][CH:39]=[CH:40][CH:41]=1)[O:1][C:2]1[C:7]2[CH:8]([CH3:18])[CH:9]([CH2:14][CH2:15][CH2:16][OH:17])[C:10]([CH3:12])([CH3:13])[O:11][C:6]=2[CH:5]=[C:4]([CH2:19][CH2:20][CH2:21][CH2:22][CH3:23])[CH:3]=1)([CH3:32])[CH3:33]

Participants

6

Reactant 4

HCID 6228Dimethylformamide2×HCID 24758Sodium hydrideHCID 94078tert-ButyldiphenylchlorosilaneHCID 18970139rac-3,4-Dihydro-5-hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanol

Product 1

HCID 189701315-[[(1,1-Dimethylethyl)diphenylsilyl]oxy]-3,4-dihydro-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanolYield 45%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

A solution of 3.17 g (8.78 mmol) of rac-3,4-Dihydro-5-hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanol in 60 mL of anhy. DMF (Aldrich) was added to a suspension of 383 mg (1 eq) of sodium hydride (Aldrich) in 20 mL of anhy. DMF (Aldrich) and the mixture stirred at RT under argon for 0.5 hr. 2.28 mL (1 eq.) of tert-butylchlorodiphenylsilane (Aldrich) was then added by syringe. After stirring for 2 hr at RT the reaction was diluted with EtOAc, washed with 0.1N aq. HCl, water, sat. aq. NaCl, dried and evaporated under reduced pressure. The residue was purified by flash chromatography on silica gel, eluting with 30% EtOAc-hexane. The fractions containing the product were combined and evaporated under reduced pressure to give 2.23 g (45%) of 5-[[(1,1-Dimethylethyl)diphenylsilyl]oxy]-3,4-dihydro-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanol as a pale yellow oil. HR EI MS: Calc M+, 558.3530; Observed, 558.3516.

Workup

  1. washwashed with 0.1N aq. HCl, water, sat. aq. NaCl
  2. customdried
  3. customevaporated under reduced pressure
  4. customThe residue was purified by flash chromatography on silica gel
  5. washeluting with 30% EtOAc-hexane
  6. additionThe fractions containing the product
  7. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-8fc73e34e5e6425d9c5a209bee189c21
Source dataset
uspto-grants-1998_10
Patent number
US05817766

Reaction notes

Loading…