Carbon Dioxide → 5,6-Dihydro-5,5-dimethyl-8-(4-methylphenyl)-2-naphthalenecarboxylic acid

Beteiligte Stoffe

Reaktionsschritte

A solution of 3,4-dihydro-1-(4-methylphenyl)-4,4-dimethyl-7-bromonaphthalene (Compound D) (250.0 mg, 0.764 mmol) in 2.0 ml of THF was cooled to −78° C. and 1.0 ml of t-butyllithium (1.68 mmol, 1.7 M solution in pentane) was added slowly. After stirring for 1 hour at −78° C. gaseous CO2 (generated by evaporation of Dry-Ice, and passed through a drying tube) was bubbled through the reaction for 1 hour. The solution was then allowed to warm to room temperature and the reaction was quenched by the addition of 10% HCl. Extraction with EtOAc was followed by washing the combined organic layers with H2O and saturated aqueous NaCl, and drying over MgSO4. Removal of the solvents under reduced pressure and washing of the solid with hexanes afforded the title compound as a colorless solid. 1H NMR (CDCl3): δ 7.94 (1H, dd, J=1.8, 8.1 Hz), 7.76 (1H, d, J=1.8 Hz), 7.45 (1H, d, J=8.1 Hz), 7.24 (4H, m), 6.01 (1H, t, J=4.7 Hz), 2.40 (3H, s), 2.36 (2H, d, J=4.7 Hz), 1.35 (6H, s).

Herkunft & Nachweise