1,1-Diethoxyethene → 7,7-Diethoxy-3,4-dimethoxybicyclo[4.2.0]octa-1,3,5-triene

HRID 536998

Reaction equation

HRID 536998 reaction equation
Br[C:2]1[CH:7]=[C:6]([O:8][CH3:9])[C:5]([O:10][CH3:11])=[CH:4][C:3]=1Br.[CH2:13]([O:15][C:16]([O:18][CH2:19][CH3:20])=[CH2:17])[CH3:14].C([Li])CCC>C1(C)C=CC=CC=1>[CH2:13]([O:15][C:16]1([O:18][CH2:19][CH3:20])[CH2:17][C:2]2[C:3]1=[CH:4][C:5]([O:10][CH3:11])=[C:6]([O:8][CH3:9])[CH:7]=2)[CH3:14]

Participants

5

Reactant 3

HCID 1376731,1-DiethoxyetheneHCID 27580334,5-DibromoveratroleHCID 178418339Butyllithium

Product 1

HCID 1176363657,7-Diethoxy-3,4-dimethoxybicyclo[4.2.0]octa-1,3,5-trieneYield 31%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

2.55 g of 1,2-dibromo-4,5-dimethoxybenzene (8.62 mmol; 2 eq) and 500 mg of 1,1-diethoxyethene (4.31 mmol; 1 eq) in 25 mL of toluene are stirred at 0° C. under argon. 3.5 mL of n-butyllithium (2.5M in hexane, 8.62 mmol; 2 eq) are added dropwise at 0° C. When the addition is complete, the reaction mixture is stirred for 22 hours at ambient temperature. The reaction mixture is then hydrolysed and extracted 3 times with ethyl acetate. The organic phases are dried and evaporated, and the crude product is purified by column chromatography over silica gel (eluant: heptane/ethyl acetate 90/10). There are obtained 333 mg of a yellow oil which crystallises at ambient temperature.

Workup

  1. additionWhen the addition
  2. extractionhydrolysed and extracted 3 times with ethyl acetate
  3. customThe organic phases are dried
  4. customevaporated
  5. customthe crude product is purified by column chromatography over silica gel (eluant: heptane/ethyl acetate 90/10)

Sources & evidence

ORD record
ord-155f72b8fd384fbb829cf894c0ec540f
Source dataset
uspto-grants-2014_10
Patent number
US08859763B1

Linked notes

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