SYNTHESIS AND PROPERTIES OF 3'-DEOXYPSICONUCLEOSIDES - ANOMERIC 1-(3-DEOXY-D-ERYTHRO-2-HEXULOFURANOSYL)THYMINES AND 9-(3-DEOXY-D-ERYTHRO-2-HEXULOFURANOSYL) ADENINES

Anomeric 1-(3-deoxy-D-erythro-2-hexulofuranosyl)thymines and 9-(3-deox y-D-erythro-2-hexulofuranosyl)adenines were prepared by tin(IV) chlori de catalyzed N-glycosylation of trimethylsilylated thymine and N-6-ben zoyladenine with methyl 3-deoxy-D-erythro-2-hexulofuranoside triacetat e or tribenzoate, respectively. These O-glycosides used as starting ma terials were obtained by deoxygenation of 1,2: 4,5-di-O-isopropylidene -beta-D-fructopyranose and subsequent acid-catalyzed methanolysis of t he resulting 3-deoxy derivative. The anomeric configuration of the nuc leosides prepared was assigned by a combination of X-ray crystallograp hy and 2D H-1 NMR spectroscopy. The conformation and hydrolytic stabil ity of these new nucleoside analogous are discussed.