9-(2-DEOXY-BETA-D-XYLOFURANOSYL)ADENINE AND 1-(2-DEOXY-BETA-D-XYLOFURANOSYL)THYMINE - PHOSPHORYLATION AND STABILITY

Abstract

Phosphorylation of 1-(2-deoxy-beta-D-xylofuranosyl)thymine (1) or 9-(2-deoxy-beta-D-xylofuranosyl)adenine (3) with phosphoryl chloride gives the cyclic 3',5'-phosphates (2 and 4a) but not the 5'-monophosphates 8a or 8b. The latter are obtained by phosphorylation of the 3'-O-benzoylated 2'-deoxy-beta-D-xylonucleosides (7a, b) and subsequent base-catalyzed removal of the benzoyl groups. Compound 3, as the parent dA, depurinates in acidic medium, a reaction which is facilitated in the case of the N6-benzoyl derivative 9b and reduced after the introduction of an amidine protecting group. N-Glycosylic bond hydrolysis of 2'-deoxy-beta-D-xylofuranosyl nucleosides is enhanced by a factor of two compared to 2'-deoxy-beta-D-ribofuranosyl nucleosides.