The reaction of 6.1 g of 3,7,11,15-tetramethyl-2,6,10,14-hexadecatetraenoic acid with glycine ethyl ester hydrochloride was conducted in the same manner as described in Example 1 except that 6.5 ml of triethylamine was used. Then, a solution of 2.7 g of potassium hydroxide in ethanol was added. The mixture was heated under reflux for 30 minutes. After the completion of the reaction, water was added and the obtained aqueous solution was extracted with ethyl acetate. The ethyl acetate layer was washed with water and dried over magnesium sulfate. The solvent was distilled off to afford 6.1 g (yield 85%) of the title compound as a pale brown oil.
