To a four-necked round-bottom flask equipped with a refluxing condenser and mechanical stirrer was added 1.5 L of dry THF under argon. Titanium trichloride (TiCl3, 200 g, 1.29 mol) was then added to the flask with stirring. After 15 minutes of stirring, powdered zinc (130 g, 2.0 mol) was added in portions and the flask was heated in hot water for 25 minutes. The reaction flask was then cooled in an ice-salt bath and the temperature of the mixture maintained at 5° to 7° C. Triethylamine (2.0 mL) was added to the suspension with caution (the reaction is extremely exothermic). The reaction started in approximately 5 to 10 minutes. After the reaction subsided, an additional amount of triethylamine (200 mL) was added and the mixture heated under reflux for 3 hours. After this period, a solution of methyl 3-tert-butyldimethylsiloxybenzoate (100 g, 0.37 mol) and 2-adamantanone (85.0 g, 0.57 mol) in 400 mL of dry THF was added dropwise to the refluxing mixture over 5 hours. The reaction mixture was then cooled to room temperature and was diluted with hexane (4 L) and the stirring continued. The suspended solids were then allowed to settle and the organic layer decanted. The black solid was washed with diethyl ether (2×1 L). Hexane (1 L) was added to the black material, followed by 1 L of water and the organic layer was removed. The aqueous layer was washed a second time with 1.5 L of hexane. The combined hexane and ether layers were then gravity filtered and the resulting solution was dried over anhydrous magnesium sulfate. Evaporation of the solvent under reduced pressure and chromatography over silica gel with 5% ethyl acetate/hexane gave 117 g (81% yield) of 2 as a clear oil.
