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

HRID 404312Notes

Reaction equation

HRID 404312 reaction equation
[CH3:1][O:2][C:3]1[CH:12]=[C:11]2[C:6]([CH2:7][CH2:8][CH2:9][C:10]2=O)=[CH:5][CH:4]=1.[Br-].[C:15]1(C([PH3+])(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.CC(C)([O-])C.[K+]>C1COCC1>[CH3:1][O:2][C:3]1[CH:12]=[C:11]2[C:6]([CH2:7][CH2:8][CH2:9][C:10]2=[CH2:15])=[CH:5][CH:4]=1

Participants

5

Reactant 3

HCID 812767-Methoxy-1,2,3,4-tetrahydronaphthalen-1-oneHCID 21951224Triphenylmethyl phosphonium bromideHCID 23665647Potassium tert-butoxide

Product 1

HCID 109650271-Methylene-7-methoxy-1,2,3,4-tetrahydronaphthaleneYield 92%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 7-methoxy-1-tetralone H4.1 (26.9 g, 153 mmol) (commercially available from Sigma-Aldrich, St. Louis, Mo., USA) and triphenylmethylphosphonium bromide (65.4 g, 183 mmol) in THF (550 mL) was added potassium tert-butoxide (1.0 M solution in THF)(183 mL, 183 mmol) via addition funnel over 1 hour. The resulting mixture was stirred at room temperature for 60 minutes after addition. The reaction was then concentrated and resuspended in hexanes (250 mL). The mixture was passed through a silica gel plug (25 g silica) and rinsed with 250 mL of hexanes. Removal of solvent gave H4.2 (24.5 g, 92% yield). MS ESI (pos.) M/E: 175 (M+H).

Workup

  1. additionvia addition funnel over 1 hour
  2. additionafter addition
  3. concentrationThe reaction was then concentrated
  4. washrinsed with 250 mL of hexanes
  5. customRemoval of solvent

Sources & evidence

ORD record
ord-64159a63cde44866b35aa7b98e8a6e4d
Source dataset
uspto-grants-2014_06
Patent number
US08748462B2

Reaction notes

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