11-Bromoundecanoic acid → 11-Bromo-1-undecanol

Participants

Reaction Steps

Sodium Borohydride (28.8 g, 0.76 mole) was dissolved in diglyme (700 ml) and THF (300 ml) and the solution cooled to 20° (dissolution of the NaBH4 is slightly exothermic). BF3OEt2 (145 g, 1.02 mole) was then added dropwise, with external cooling, at such a rate to keep the temperature of the mixture below 15°. After the addition was complete the mixture was stirred for 0.5 hour at 10°. This reducing agent was then added slowly to a solution of 11-bromoundecanoic acid (200 g, 0.76 mole) in THF (400 ml) keeping the temperature below 20°. After the addition was complete, the reaction was stirred at room temperature for 1.5 hours then quenched by pouring onto water (3 L) and concentrated HCl (100 ml). The quenched mixture was stirred for 0.5 hour at room temperature then cooled to 5°. The crystalline product was filtered off, washed with water (3×1 L) and dried under vacuum to give 11-bromoundecanol (189.2 g, 99.2%).

Provenance & Evidence