Methyl 9-dodecenoate → 9-Dodecen-1-ol

Participants

Reaction Steps

To a dry 2 L 3-neck round bottom flask fitted with a nitrogen inlet and outlet, thermocouple, condenser, mechanical stirrer and pressure-equalizing dropping funnel was added lithium aluminum hydride (30.10 g, 0.754 mol, 95% technical grade solid) in one portion, under a positive pressure of nitrogen. The metal hydride was suspended in anhydrous tetrahydrofuran (500 mL) and the mixture cooled on an ice bath. Methyl 9-dodecenoate (200 g, 0.942 mol) was added dropwise via addition funnel to the stirred lithium aluminum hydride suspension over 1 h at such a rate as to maintain the internal temperature below 50° C. When the reaction exotherm subsided, the external cooling bath was removed and the resulting viscous mixture was stirred for a further 8 h at ambient temperature. Complete consumption of starting material was confirmed by thin layer chromatography and by FTIR. The reaction was quenched by the careful addition of the reactor contents to a 4 L Erlenmeyer flask containing chilled concentrated aqueous sodium chloride (300 mL). The reactor was rinsed with ethyl acetate (100 mL) then 10% (v/v) aqueous sulfuric acid (100 mL); both rinse aliquots were combined with the reaction neutralization mixture. An additional aliquot of 10% (v/v) aqueous sulfuric acid was added to neutralize the aqueous phase then the biphasic neutralization mixture was transferred to a separatory funnel. The aqueous phase was partitioned and washed with ethyl acetate (100 mL×2). The combined organic phases were successively washed with concentrated aqueous sodium bicarbonate (100 mL), brine (100 mL), dried (MgSO4) then filtered. The organic phase was concentrated in vacuo, giving 9-dodecen-1-ol (165 g, 95%) as clear, colorless oil.

Provenance & Evidence