4-Hydroxy-4-[3,4-dimethoxy-2-(1-methylethyl)phenyl]-3-methylbut-2-enoic Acid → 4-[3,4-Dimethoxy-2-(1-methylethyl)phenyl]-3-methylbutanoic Acid

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Reaction Steps

Compound 9 (7.00 g, 23.8 mmol) in 100 mL of acetic acid was hydrogenated on a Parr hydrogenator with 0.4 g of 10% palladium on carbon and 60 psi hydrogen pressure at 60° C. for 20 h. The reaction mixture was vacuum filtered through celite and the celite was washed with ether. The solvent was evaporated in a fume hood and the residual oil was distilled bulb to bulb (170° C./1 torr) to give 5.95 g (21.2 mmol, 89%) of 10 as an amber oil which crystallized on standing to form nearly colorless microcrystals: mp 100°-101° C. (lit14 mp not reported); IR: 1710 (carbonyl) cm-1 ; 1H NMR δ 0.982 (d, J=6.1 Hz, 3 H), 1.33 (d, J=7.1 Hz, 6 H), 2.0-2.7 (m, 5 H), 3.14 (sept, J=7.1 Hz, 1 H), 3.82 (s, 3 H), 3.85 (s, 3 H), 6.62 (d, J=8.0 Hz, 1 H), 6.75 (d, J=8.0 Hz, 1 H). Anal. (C16H24O4) C,H.

Provenance & Evidence