A solution of 6-bromo-4-tert-butyl-7-ethoxy-1,1-dimethyl-1,2-dihydronaphthalene (Compound A-6, 350 mg, 1.04 mmol), bis(pinacolato)diboron (370 mg, 1.46 mmol), and potassium acetate (305 mg, 3.12 mmol) in dimethylformamide (8 mL) was purged with argon for 15 minutes. [1, 1-bis(disphenylphosphino)ferrocene]dichloropalladium(II) (1:1 complex with dichloromethane, 82 mg, 0.1 mmol) was added and purged with argon for another 5 min. The reaction was continuously stirred at 80° C. for 4 days under argon. Thereafter the reaction was cooled to room temperature and quenched with water. The reaction mixture was extracted with ethyl acetate. The organic layer was washed successively with water, brine, dried over Na2SO4, and concentrated in vacuo. Purification by column chromatography (silica gel, 10 to 20% ethyl acetate in hexane) yielded a mixture of 2-(8-tert-butyl-3-ethoxy-5,5-dimethyl-5,6-dihydronaphthalen-2-yl)-4,4,5,5-tetramethyl [1,3,2]dioxaborolane (Compound A-8) and 2-(8-tert-butyl-1-(3-ethoxy-5,5-dimethyl-5,6-dihydro-naphthalen-2-yl)boronic acid (Compound A-10). The above mixture of Compounds A-8 and A-10, ethyl 7-iodo-3-methyl-octa-2E,4E,6Z-trienoate (Compound A-11, 130 mg, 0.43 mmol), tetrakis(triphenylphosphine)palladium(0) (40 mg, 0.03 mmol), and 2M sodium carbonate (1 mL, 2 mmol) in toluene (4 mL) and ethanol (2 mL) was heated to 100° C. for 40 h. The reaction was cooled to room temperature and extracted with ethyl acetate. The organic layer was washed with brine, dried over Na2SO4, and concentrated in vacuo. Purification by column chromatography (silica gel 1% to 2% ethyl acetate in hexane) yielded the title compound as an oil.
