7-Methoxy-1,2,3,4-tetrahydronaphthalen-1-one → 1-Methylene-7-methoxy-1,2,3,4-tetrahydronaphthalene

HRID 1880589Notes

Reaction equation

HRID 1880589 reaction equation
[CH2:1]([Li])CCC.[CH3:6][O:7][C:8]1[CH:17]=[C:16]2[C:11]([CH2:12][CH2:13][CH2:14][C:15]2=O)=[CH:10][CH:9]=1>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C1COCC1>[CH3:6][O:7][C:8]1[CH:17]=[C:16]2[C:11]([CH2:12][CH2:13][CH2:14][C:15]2=[CH2:1])=[CH:10][CH:9]=1

Participants

5

Reactant 2

HCID 812767-Methoxy-1,2,3,4-tetrahydronaphthalen-1-oneHCID 178418339Butyllithium

Product 1

HCID 109650271-Methylene-7-methoxy-1,2,3,4-tetrahydronaphthalene

Reagents, catalysts & solvents 2

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

n-Butyl lithium (1.6M, 6.2 mL, 9.92 mmol) was added dropwise to a THF (20 mL) solution containing methyltriphenylphosphonium bromide (3.65 g, 10.22 mmol) cooled in an ice bath. The solution was stirred at room temperature for 3 hours. A THF (5 mL) solution of 7-methoxy-3,4-dihydronaphthalen-1(2H)-one (1 g, 5.68 mmol) was added dropwise. The solution was then stirred at 60° C. overnight. The solution was partitioned between ethyl ether and water. The organic phase was washed with water (3×) and brine and dried over MgSO4. The filtered solution was concentrated and the residue purified by silica gel chromatography using a hexanes/ethyl acetate gradient to give the title compound. 1H NMR (500 MHz, CDCl3): δ 7.25 (d, J=2.6 Hz, 1H); 7.10 (d, J=8.3 Hz, 1H); 6.86 (dd, J=2.6, 8.4 Hz, 1H); 5.55 (s, 1H); 5.05 (s, 1H); 3.88 (s, 3H); 2.86 (t, J=6.3 Hz, 2H); 2.61 (t, J=6.2 Hz, 2H); 1.96-1.92 (m, 2H). LCMS1 3.79 min. (M+1)=175

Workup

  1. temperaturecooled in an ice bath
  2. stirringThe solution was then stirred at 60° C. overnight
  3. customThe solution was partitioned between ethyl ether and water
  4. washThe organic phase was washed with water (3×) and brine
  5. dry with materialdried over MgSO4
  6. concentrationThe filtered solution was concentrated
  7. customthe residue purified by silica gel chromatography

Sources & evidence

ORD record
ord-773b9212d34a46559e9d6e782e14cd34
Source dataset
uspto-grants-2012_11
Patent number
US08318760B2

Reaction notes

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