2'-Deoxyisoguanosine and Base-Modified Analogues: Chemical and Photochemical Synthesis

Article abstract of DOI:10.1002/hlca.19910740816

The synthesis of 2'-deoxyisoguanosine (2), and the pyrrolo<2,3-d>pyrimidine and pyrazolo<3,4-d>pyrimidine 2'-deoxyribonucleosides 3 and 4 is described.Condensation of the imidazole precursor 5 with benzoyl isocyanate followed by reaction with ammonia gave 2.Its N(7) regioisomer was obtained from 6.Compound 2 was also prepared by the photochemically induced conversion of 2-chloro- and 2-bromopurine 2'-deoxyribofuranosides 9a and 10, respectively, in aqueous solution.The photo reaction was further used for the synthesis of the compounds 3 and 4 starting with the amino-chloro-2'-deoxynucleosides 9b and 9c, respectively.