LITHIATION OF 5,6-DIHYDROURIDINE: A NEW ROUTE TO 5-SUBSTITUTED URIDINES

Article abstract of DOI:10.1016/S0040-4020(01)96481-6

2',3'-O-Isopropylidene-5'-O-methoxymethyl-5,6-dihydrouridine (2) was found to serve as an "amide α-anion" upon lithiation with LDA.Reactions of the anion with acid chlorides followed by phenylselenation and oxidative elimination furnished 5-acyluridines.For the preparation of 5-alkyluridines, initial introduction of phenylselenenyl group at the C-5 of 2 appeared to be effective.Alkylation of its α-selenenyl carbanion and subsequent generation of 5,6-double bond produced 5-alkyluridines.These routes constitute a new entry to 5-substituted uridines.