Uridine-3′-phosphorothiolate triesters bearing lipophilic moieties were prepared via Michaelis-Arbuzov chemistry. Subsequent deprotection of the S-cholesteryl phosphorothiolate triester afforded the corresponding diester which underwent spontaneous Cyclization to cleanly afford uridine 2′, 3′-cyclic phosphate. This transesterification reaction could be expedited by treatment with iodine under mild, neutral conditions.
