Nucleosides osmium tetroxide

C-Acyclic nucleoside analogs of inosine and guanosine 8-[(/ 5)-2,3-dihydroxypropyl]imidazo[l,5-fl]-l,3,5-triazin-4(3//)-ones were synthesized. The route involved the cyclization and rearrangement of 5-acylamino-5-allyl-6-amino-4,5-dihydropyrimidin-4-ones (1122) to 8-allylimidazo[l,5-a]-l,3,5-triazin-4(3//)-ones (1123). Osmium tetroxide hydroxylation gave 1124. None of these analogs showed appreciable antiviral or antitumor cell activity (84NAR263 87MI6). 

K. Burton, Biochem. J., 104, 686 (1967). Oxidation of Pyrimidine Nucleosides and Nucleotides by Osmium Tetroxide. 

Anhydro-l,4-di-0-benzyl-L-threitol on reaction with allylmagnesium bromide, osmium tetroxide, sodium periodate then HCl affords methyl 3-C-(benzyloxymethyl)-2,3-dideoxy-L-r/ireo-pentofuranoside as a useful intermediate for the synthesis of 2 3 -dideoxy-3 -C-(hydroxymethyl)-4 -thionucleosides. In an alternative route to such nucleosides the intermediate branched-sugar 50 was prepared in which the hydroxymethyl group was introduced into the 3-position by a light-induced addition of methanol to 6-O-rerr-butyldimethylsilyl-D-g/yceru-pent-2-eno-1,4-lactone (see Vol. 26, p. 242, ref. 159). ... 

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