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 0.5N 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.
