Highly efficient and regioselective phosphorylation of sphingolipids by phase-transfer catalysis

Phosphorylation of D-erythro-sphingosine and its N-BOC or N-palmitoyl derivatives with trimethyl phosphite was carried out in 72-92% yield at room temperature for 20 min in a biphasic system comprised of dichloromethane/aqueous solutions of NaOH or K₂CO₃ using 1,2- dibromotetrachloroethane as a source of halogen and cetyl pyridinium bromide as a phase-transfer catalyst. These are the first reported examples of a highly selective O- and N-phosphorylation of sphingolipids by the phase-transfer catalysis. Our studies show that the developed phosphorylation protocol works as a modular process, in which the synthetic outcome is controlled by a type of the used base, catalyst and solvent system.