A solution of 1,3-dicyclohexylcarbodiimide (23.7 g) and 4-(N,N-dimethylamino)pyridine (15.9 g) in methylene chloride (200 ml) was added to a solution of 1-(z,z,z-octadeca-6,9,12-trienoyloxy)-3-hydroxypropane (33.6 g) and z-octadeca-9-enoic acid (30 g) in methylene chloride (400 ml) under nitrogen at room temperature. On completion of reaction as evidenced by tlc analysis the solution was diluted with hexane, filtered, concentrated and purified by thy column chromatography to yield 1-(z,z,z-octadeca-6,9,12-trienoyloxy)-3-(z-octadeca-9-enoyloxy)propane as a free flowing pale yellow oil.
