A solution of 27-oleoyloxy-heptacosanoic acid (2 g; 2.89 mmoles) in chloroform (30 ml) and triethylamine (1.6 ml; 11.5 mmoles) was added in 30 minutes to a stirred solution of 0.5 grams of p-toluenesulphonyl chloride (0.5 g; 2.6 mmoles) in chloroform (40 ml) under nitrogen while keeping the temperature at 50° C. After stirring for 1 hour at 50° C. phytosphingosine (0.8 g; 2.52 mmoles) was added and stirring was continued for 2 hours at 50° C. After cooling the mixture was washed with 50 ml of 0.5 N hydrochloric acid, 50 ml of water and brine respectively. The organic layer was evaporated in vacuum and the residue was crystallized from 50 ml of warm 2-propanol under nitrogen giving 2.03 grams of the impure title compound. Purification over 40 grams of silica gel (Flash 30-60 μm) with chloroform/methanol=9/1 and subsequent crystallization from 40 ml of hot isopropanol gave 0.74 g of the title compound.
