4-[2-[5,6-Dihydro-5,5-dimethyl-8-[[(trifluoromethyl)sulfonyl]oxy]-2-naphthalenyl]ethynyl]benzoic acid ethyl ester → Ethyl 4-[(7,8-dihydro-8,8-dimethyl-5-(2-thienyl)naphth-3-yl)ethynyl]benzoate

Participants

Reaction Steps

Employing the same general procedure as for the preparation of ethyl 4-[(5,6-dihydro-5,5-dimethyl-8-(4-methylphenyl)-2-naphthalenyl)ethynyl]benzoate (Compound 1), 250.0 mg (0.52 mmol) of ethyl 4-[(5,6-dihydro-5,5-dimethyl-8-(trifluoromethylsulfonyl)oxy-2-naphthalenyl)ethynyl]benzoate (Compound G) was converted into the title compound (colorless solid) using 186.8 mg (1.37 mmol) of zinc chloride 37.1 mg (0.03 mmol) of tetrakis(triphenylphosphine)palladium(0) and 2-lithiothiophene (prepared by the addition of 65.9 mg (0.69 ml, 1.03 mmol) of n-butyllithium (1.5M solution in hexane) to a cold solution (−78° C.) of 86.5 mg (1.03 mmol) of thiophene in 1.0 ml of THF). PMR (CDCl3): δ 1.33 (6H, s), 1.36 (3H, t, J=7.1 Hz), 2.38 (2H, d, J=4.7 Hz), 4.34 (2H, q, J=7.2 Hz), 6.25 (1H, t, J=4.7 Hz), 7.13 (2H, m), 7.47 (4H, m), 7.62 (2H, d, J=8.5 Hz), 8.00 (2H, d, J=8.5 Hz).

Provenance & Evidence