Sodium borohydride → Benzyl 9-hydroxynonanoate

Participants

Reaction Steps

The product from 11a (12.9 g; 46.3 mmol) was added in portions to a stirred mixture of sodium borohydride (1.70 g; 45.0 mmol) in dry tetrahydrofuran (25 mL). After the evolution of hydrogen subsided, a solution of boron trifluoride dimethyl etherate (4.6 mL; 5.7 g; 50 mmol) in dry tetrahydrofuran (15 mL) was added drop-wise. The exothermic reaction was moderated with a cold water bath. After stirring 4 h at ambient temperature, the reaction mixture was hydrolyzed with cold water (20 mL). The mixture was separated and the organic phase was evaporated; the residue was mixed with water (20 mL) and dichloromethane (70 mL) to give an emulsion that separated on standing overnight. The organic layer was washed with water (4×15 mL) until the washings were neutral to pH paper. Following drying (Na2SO4), filtration, and evaporation 11.95 g (98%) product was obtained (oil).

Provenance & Evidence