3-Hydroxy-2,2-dimethylpropionaldehyde → (Z)-2,2-dimethyl-3-dodecen-1-ol

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Reaction Steps

A 5.6 g (11.9 mmoles) sample of (n-nonyl)triphenylphosphonium bromide was coupled with 1.86 g (10 mmoles) of the tetrahydropyranyl ether of hydroxypivaldehyde using the Wittig reaction conditions described in the previous examples (THF:HMPT, 2:1; 7 ml of 1.6 M n-butyllithium in hexane; -78° C.). The crude product (3.4 g) was chromatographed on silica gel. Hexane-ether (7:3) eluted 2.8 g (95%) of (Z)-2,2-dimethyl-3-dodecen-1-ol tetrahydropyranyl ether, which was dissolved in 28 ml of methanol and subsequently treated with 0.3 ml of 2 N HCl. After stirring for 3 hours at room temperature, most of the solvent (about 20 ml) was removed in vacuo, and the residue was extracted with ether. The ethereal solution was washed with brine, saturated NaHCO3 solution, brine, dried over MgSO4, and the solvent was evaporated under reduced pressure. The crude alcohol (2.2 g) was chromatographed on silica gel to afford 1.8 g (85%) of (Z)-2,2-dimethyl- 3-dodecen-1-ol as an oil.

Provenance & Evidence