Iodine monochloride facilitated deglycosylation, anomerization, and isomerization of 3-substituted thymidine analogues.

The reaction of thymidine, 3-mono-, and 3,3',5'-trialkylsubstitued thymidine analogues with iodine monochloride (ICl) was investigated. Treatment with ICl resulted in rapid deglycosylation, anomerization, and isomerization of thymidine and 3-substituted thymidine analogues under various reaction conditions leading to the formation of the nucleobases as the major products accompanied by minor formation of α-furanosidic-, α-pyranosidic-, and β-pyranosidic nucleosides. On the other hand, 3,3',5'-trisubstitued thymidine analogues were only deglycosylated and anomerized.