Lithium Chloride → Ethyl 4-[(7,8-dihydro-8,8-dimethyl-5-(1,1-dimethylethyl)naphth-3-yl)ethynyl]benzoate

Participants

Reaction Steps

A mixture of 35.1 mg (0.39 mmol) of cuprous cyanide and 16.6 mg (0.39 mmol) of lithium chloride was flame dried under vacuum, cooled to room temperature and dissolved in 1.5 ml of THF. This solution was cooled to -78° C. and 50.2 mg (0.46 mL, 0.784 mmol) of tert-butyllithium (1.7M solution in pentane) was added forming a clear yellow solution. The reaction mixture was stirred at -78° C. for 15 minutes and then 125.0 mg (0.26 mmol) of ethyl 4-[(5-trifluoromethylsulfonyloxy-7,8-dihydro-8,8-dimethylnaphth-3-yl)ethynyl]benzoate (Compound 66) was added as a solution in 0.5 ml of THF. After 10 minutes the reaction was quenched at -78° C. with 1.5 ml of a 2:1 (v/v) mixture of sat. aqueous NH4Cl and 5% NaOH. The mixture was extracted with EtOAc and the combined organic layers were washed with water and brine. The organic phase was dried over MgSO4, concentrated in vacuo and purified by column chromatography (silica, 5% EtOAc-hexanes) to give a clear yellow oil (7:5 ratio of title compounds). The two compounds were separated by HPLC (partisil 10, 2% EtOAc-hexanes) to give the title compounds as colorless oils.

Provenance & Evidence