Figure 2. Synthesis of hexadecyloxypropyl cytarabine 5’-monophosphate and hexadecyloxypropyl cytarabine 3’,5’-cyclic monophosphate. The following reagents were used: a) 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane, pyridine; b) benzoyl chloride, pyridine; c) tetrabutylammonium fluoride, HOAc, CH₃CN; d) benzoyl chloride, pyridine, e) hexadecyloxypropyl phosphate, N,N-dicyclohexylcarbodiimide, pyridine; f) ammonia/methanol; g) 2,4,6-triisopropylbenzenesulfonyl chloride, pyridine.