1 g (2.88 mmol) of ethyl 4-[(5,6,7,8-tetrahydro-8,8-dimethyl-5-oxonaphth-3-yl)ethynyl]benzoate (Compound 9) was converted into the title compound using 60 mg (1.6 mmol) of sodium borohydride. The procedure was as follows: To a cold solution (0° C.) of Compound 9 in 5 ml of THF and 10 ml of ethanol was added sodium borohydride. The mixture was stirred for 6 hours, diluted with water (10 ml) and extracted with Et2O (4×40 ml). The combined organic layers were washed with 10% HCl (5 ml), 10% aqueous NaHCO3 (10 ml) and brine (10 ml), dried over MgSo4 and concentrated in vacuo to give the title compound as a white solid.
