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

Participants

Reaction Steps

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.

Provenance & Evidence