To a mixture of 0.650 g. (16.91 mmole) of sodium borohydride and 3.17 g. (45.2 mmoles) of 2-methyl-2-butene in 40 ml. of diglyme cooled to -5° C. under an inert atmosphere is added over 15 minutes 3.24 g. (22.6 mmoles) of boron trifluoride etherate and the resulting mixture is stirred at 0° C. for 2 hours. To this mixture is then added over 5 minutes 8.32 g. (22.6 mmoles) of 3-triphenylmethoxyl-1-octyne (Example 127) in 10 ml. diglyme, the cooling bath is removed, and the mixture is stirred at ambient temperature for 1.5 hours. The mixture is cooled to 0° C. and 6.0 g. of finely divided anhydrous trimethylamine oxide is added over 10 minutes. The cooling bath is removed and the mixture is stirred at ambient temperatures for 0.5 hour. The mixture is then poured into 200 ml. of 15 % sodium hydroxide solution, a solution of 16 g. (63 mmoles) of iodine in 20 ml. of tetrahydrofuran is added immediately, and the resulting mixture is stirred for 0.5 hour. The organic phase is separated and the aqueous phase is washed with ether. The combined organic phase and washings are decolorized with 5% sodium thiosulfate solution, washed with saturated brine, dried (Na2SO4), and evaporated. The residue is dry-columned chromatographed upon alumina using hexane as eluent and the title compound is isolated as an oil.
