A solution of 2-hydroxy-3-octanoyloxypropyl octanoate (5.0 g.) in ether (30 ml.) was stirred with triethylamine (2.04 ml.) and glutaric anhydride (1.66 g.) for 3.5 hours. Further glutaric anhydride (0.8 g.) was then added together with triethylamine (1.0 ml.). This mixture was heated under reflux until no further starting octanoate could be detected by thin layer chromatography (silica: methylene chloride). The cooled reaction mixture was washed with 1M hydrochloric acid (2×20 ml.), then with water (2×20 ml.), dried (MgSO4) and evaporated to give 2-octanoyloxy-1-(octanoyloxymethyl)ethyl hydrogen glutarate as an oil (6.62 g.); NMR (CDCl3): 0.9 (6H, t, CH3), 1.1-2.1 (22H, m, CH2), 2.4 (8H, m, CH2CO), 4.0-4.4 (4H,m, CH2O), 5.1-5.4 (1H, br.t, CHO), 9.6 (1H, br.s, CO2H)ppm. Mass spectrum (major diagnostic peaks based on M=458, using chemical ionisation techniques): m/e 476 (M+NH4), 360 (M +NH4 --HO2C.(CH2)3.CO2H)
