Hydrochloric Acid → 3-Nonen-5-ol, 4,8-dimethyl-

Participants

Reaction Conditions

Reaction Steps

69.5 g (2.9 g-atoms) of magnesium are placed in 500 ml of absolute ether Subsequently, a solution of 438 g of isoamyl bromide, which contains about 1.5% of n-amyl bromide in accordance with gas chromatography, in 1.2 1 of absolute ether is added dropwise so that the exothermic reaction keeps the ether constantly at the boiling point After completion of the addition, the mixture is held at reflux temperature for a further 30 minutes. The Grignard solution is then cooled to 10° C. 236.5 g (2.41.mol) of 2-methyl 2-pentenal in 600 ml of absolute ether are then added dropwise within 40 minutes, the temperature then lying permanently between 10° C. and 20° C. In order to complete the reaction, the mixture is held at reflux temperature for a further 1 hour. The mixture is subsequently added to ice, decomposed with aqueous hydrochloric acid, the ethereal solution is washed neutral with soda and saturated sodium chloride solution and thereupon dried. The crude product (480 g) remaining behind after distillation of the solvent is fractionally distilled over a Widmer column and gives 312 g of 2,6-dimethyl-6-nonen-5-ol (III) of boiling point 62° C./0.05 Torr, nD25 =1.4479, which contains 1.5% of 4-methyl-3-decen-5-ol in accordance with gas chromatography (Carbowax, 130° C.).

Provenance & Evidence