Ethyl 3-hydroxy-3-methylnonanoate → 3-Methylnonane-1,3-diol

Participants

Reaction Steps

To a slurry of lithium aluminium hydride (12.3 g, 0.325 mol) in diethyl ether (300 ml), under nitrogen and cooled in an ice-bath, was added dropwise a solution of ethyl 3-methyl-3-hydroxynonanoate (70.0 g, 0.325 mol) in diethyl ether (300 ml). The resultant mixture was boiled at reflux for 1 hr, then cooled in an ice-bath. Excess lithium aluminium hydride was destroyed by successive dropwise addition of water (12 ml), 10% sodium hydroxide solution (12 ml) and water (36 ml). The reaction mixture was filtered, the filter cake was washed with diethyl ether (2×100 ml) and the filtrate was washed with saturated sodium chloride solution (1×250 ml) and then dried (Na2SO4) and filtered, and the filtrate was concentrated in vacuo to give 3-methyl-3-hydroxynonan-1-ol (55.0 g) as an oil (i.r.(cm-1), OH, 3500). 3-Methyl-3-hydroxy-nonan-1-ol (55.0 g, 0.316 m) was dissolved in pyridine (235 ml) and cooled to 0° C. with stirring. p-Toluenesulphonyl chloride (63.5 g, 0.332 mol) was added portionwise and the resultant mixture stirred for 45 minutes at 0° C. The reaction mixture was stored in a refrigerator for 15 hr and then poured into iced-water (200 ml). The reaction mixture was extracted with diethyl ether (3×200 ml), and the combined extracts were washed with 10% hydrochloric acid (2×200 ml), and saturated sodium chloride solution (3×200 ml) and then dried (Na2SO4). This mixture was filtered, and the filtrate was concentrated at room temperature in vacuo to leave a gum (100 g). This gum was mixed with petrol (b.pt. 60°-80° C., 400 ml) and gradually cooled to -78° C. with stirring, and the petrol was decanted. Residual petrol was removed by evaporation in vacuo at room temperature to give 1-(p-toluenesulphonyloxy)-3-methylnonan-3-ol (90.0 g) as a gum.

Provenance & Evidence