4-Methyl-m-anisic acid → 6-methoxy-7-methyl-3,4-dihydronaphthalen-1(2H)-one

HRID 653743Notes

Reaction equation

HRID 653743 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:9]=[CH:10][C:11]=1[CH3:12])[C:6](O)=O.[Cr](Cl)([O-])(=O)=[O:14].[NH+]1C=C[CH:21]=[CH:20][CH:19]=1>C1COCC1>[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:9](=[CH:10][C:11]=1[CH3:12])[C:21](=[O:14])[CH2:20][CH2:19][CH2:6]2

Participants

4

Reactant 2

HCID 815794-Methyl-m-anisic acidHCID 178418287HCID 178418287, compound

Product 1

HCID 113559636-methoxy-7-methyl-3,4-dihydronaphthalen-1(2H)-one

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

3-Methoxy-4-methylbenzoic acid (30 g) was reduced to the benzylic alcohol with BH3 in THF (181 ml of 1 M solution). Oxidation of this product (28.7 g) with pyridinium chlorochromate (71g) gave the benzaldehyde derivative (21.3 g). Treatment of this alde hyde (19.6 g) with BrPh P(CH ) COOH (54.5 g) under Wit tig conditions afforded 4-(3-methoxy-4-methylphenyl)-3-butene carboxylic acid (26.9 g). Catalytic reduction of this product followed by polyphosphoric acid (PPA) cyclization gave the desired tetralone.

Sources & evidence

ORD record
ord-bea21ffd3d0d4df499a5b561d2f42300
Source dataset
uspto-grants-1992_07
Patent number
US05128362

Reaction notes

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