2,2,5,5-Tetramethyltetrahydro-3-ketofuran → 4-(5-Bromo-2-ethylbenzylidene)-2,2,5,5-tetramethyldihydrofuran-3-one

HRID 879051Notes

Reaction equation

HRID 879051 reaction equation
[CH3:1][C:2]1([CH3:10])[C:6](=[O:7])[CH2:5][C:4]([CH3:9])([CH3:8])[O:3]1.C[O-].[Na+].[Br:14][C:15]1[CH:16]=[CH:17][C:18]([CH2:23][CH3:24])=[C:19]([CH:22]=1)[CH:20]=O>COCCOC.C(OCC)C>[Br:14][C:15]1[CH:16]=[CH:17][C:18]([CH2:23][CH3:24])=[C:19]([CH:22]=1)[CH:20]=[C:5]1[C:4]([CH3:9])([CH3:8])[O:3][C:2]([CH3:10])([CH3:1])[C:6]1=[O:7]

Participants

6

Reactant 3

HCID 1385112,2,5,5-Tetramethyltetrahydro-3-ketofuranHCID 10942334Sodium MethoxideHCID 547723895-Bromo-2-ethylbenzaldehyde

Product 1

HCID 668231984-(5-Bromo-2-ethylbenzylidene)-2,2,5,5-tetramethyldihydrofuran-3-oneYield 94.9%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 80711,2-DimethoxyethaneSolvent2×

Procedure

To an ice-cold solution of dihydro-2,2,5,5-tetramethyl-3(2H)-furanone (13.4 g, 94.34 mmol) in anhydrous 1,2-dimethoxyethane (32 ml) is added sodium methoxide (5.6 g, 103.8 mmol) in one portion, and the reaction mixture is stirred at this temperature for 5 minutes. To the resulting slurry is then added a solution of 5-bromo-2-ethyl-benzaldehyde (20 g, 94.34 mmol) in 1,2-dimethoxyethane (32 ml) dropwise over 10 minutes. The solution is next stirred at 0° C. for 1 hour, then diluted with diethyl ether and washed with 2M hydrochloric acid (×2). Organic fractions are combined, dried over magnesium sulphate, filtered and the filtrate evaporated in vacuo to afford 4-(5-bromo-2-ethylbenzylidene)-2,2,5,5-tetramethyldihydrofuran-3-one (30.2 g) as a yellow liquid.

Workup

  1. stirringnext stirred at 0° C. for 1 hour
  2. washwashed with 2M hydrochloric acid (×2)
  3. dry with materialdried over magnesium sulphate
  4. filtrationfiltered
  5. customthe filtrate evaporated in vacuo

Sources & evidence

ORD record
ord-2ee4097671804ef6b0352b36c8cb3849
Source dataset
uspto-grants-2015_03
Patent number
US08987476B2

Reaction notes

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