Preparation of selenoanhydro- and telluroanhydroglycofuranosides and some corresponding nucleosides Original Research Article

Methyl 2,3-anhydro-α-d-ribofuranoside (3a) was transformed into methyl 2-seleno-2,5-anhydro-α-d-arabinofuranoside (5a) and methyl 3-seleno-3,5-anhydro-α-d-xylofuranoside (6a) in two steps via the reaction of the C-5 mesylate of 3a, methyl 2,3-anhydro-5-O-mesyl-α-d-ribofuranoside (4a), with sodium hydrogen selenide. The corresponding β anomer of 3a yielded methyl 3-seleno-3,5-anhydro-β-d-xylofuranoside as the main product and only traces of methyl 2-seleno-2,5-anhydro-β-d-arabinofuranoside. Sodium hydrogen telluride transformed 4a into methyl 2-telluro-2,5-anhydro-α-d-arabinofuranoside. Starting from 5a we prepared 1-(2-seleno-2,5-anhydro-α-d-arabinofuranosyl)uracil and the analogous thymidine nucleoside. Compound 6a could not be transformed into nucleosides.