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-pyridyl)naphth-3-yl)ethynyl]benzoate

Participants

Reaction Steps

Employing the same general procedure as for the preparation of ethyl 4-[(7,8-dihydro-8,8-dimethyl-5-(2-thiazolyl)naphth-2-yl)ethynyl]benzoate (Compound 67), 250.0 mg (0.52 mmol) of ethyl 4-[(5-trifluoromethylsulfonyloxy-7,8-dihydro-8,8-dimethylnaphth-3-yl)ethynyl]benzoate (Compound 66) was converted into the title compound (colorless solid) using 142.4 mg (1.045 mmol) of zinc chloride, 24.1 mg (0.02 mmol) of tetrakis(triphenylphosphine)palladium(0) and 2-lithiopyridine (prepared by the addition of 100.6 mg (0.97 ml, 1.57 mmol) of tert-butyllithium (1.5M solution in pentane) to a cold solution (-78° C.) of 123.8 mg (0.784 mmol) of 2-bromopyridine in 1.0 mL of THF).

Provenance & Evidence