To a solution of N-hydroxysuccinimide ester of 3-(9-octadecenoyloxy)-11-eicosenoic acid (3 g) in N,N-dimethylformamide (30 ml) was added a solution of L-valine (4.42 g) and a 1N sodium hydroxide solution (37 ml) at 0° C. The resulting mixture was stirred at ambient temperature overnight. The reaction mixture was acidified with 1N hydrochloric acid solution, extracted with ethyl acetate, washed with water and dried over magnesium sulfate. Ethyl acetate was distilled off to give powder of N-[3-(9-octadecenoyloxy)-11-eicosenoyl]-L-valine (2.7 g).
