Methanol → 3,5-Dimethyldodecanoic acid

In a nitrogen atmosphere, the crude product (1.22 g, 0.00452 mol) of ethyl 3,5-dimethyldodecanoate (7Et) produced in the method of Example 3-1, methanol (1 ml), a 25% by weight aqueous sodium hydroxide solution (3 ml) were placed in a reaction vessel and stirred at 65° C. for 2 hours. After addition of water, the resulting mixture was washed with a hexane-tetrahydrofuran mixture. The aqueous phase was made acidic in addition of 20% by weight hydrochloric acid, followed by extraction with a hexane-tetrahydrofuran mixture. The organic phase thus obtained was dried over magnesium sulfate and then concentrated under reduced pressure. The concentrate thus obtained was distilled under reduced pressure (bp: from 130 to 140° C./2 mmHg) to obtain 3,5-dimethyldodecanoic acid (5) (1.03 g, 0.00452 mol). A total yield of the three steps from the 2-methylnonyl chloride (1 Cl) was 60%.