Nucleosides. IV. Synthesis and reactions of 2',3',5'-trichloro-2',3',5'-trideoxy-2',3'-secouridines.

2', 3', 5'-Trichloro-2', 3', 5'-trideoxy-2', 3'-secouridines (2a, b) were synthesized from uridine or 5-fluorouridine by a combination of sodium metaperiodate oxidation, sodium borohydride reduction, and chlorination with Vilsmeier-Haack reagent. Reaction of 2a, b with base gave some new pyrimidine acyclonucleosides (3-5) and (uracil-l-yl)-1, 4-dioxanes (8, 9). The preparation of 5'-chloro-5'-deoxy-2', 3'-secouridine (11) from 5'-chloro-5'-deoxyuridine (10) and its conversion into (uracil-l-yl)-1, 4-dioxane 12 and 5'-deoxy-2', 3'-secouridine (13) are also described.