1-Bromo-2-methylpropane → 2-(Benzylmethylamino)-3,7,11-trimethyl-3,7-dodecanediol

Participants

Reaction Steps

To a solution of isobutylmagnesium bromide prepared from 14.6 9 of magnesium, 68.5 9 of isobutyl bromide and 500 ml of diethyl ether was added a solution of 34 g of 4,8-dimethyl-1-nonen-4-ol in 100 ml of diethyl ether dropwise under ice-cooling. After completion of the addition, 2.5 g of titanocene dichloride was added to the above solution at room temperature and the mixture was stirred at that temperature for 18 hours. Then, 38.2 g of 3-(benzylmethylamino)-2-butanone was added dropwise under ice-cooling and the mixture was stirred at that temperature for 30 minutes. The reaction mixture was poured into a saturated aqueous solution of ammonium chloride and extracted with diethyl ether. The ether was distilled off, and after addition of chloroform, the residue was washed with a saturated aqueous solution of sodium chloride and a small amount of aqueous sodium hydrogen carbonate. After drying over anhydrous sodium sulfate, the chloroform was distilled off and the residue was subjected to silica gel column chromatography (elution with 95% methylene chloride-5% triethylamine) to give 11.3 g of 2-(benzylmethyl-amino)-3,7,11-trimethyl-3,7-dodecanediol [Compound (71)]. Yield 17%.

Provenance & Evidence