Pyrazolo[3,4-d]pyrimidine ribonucleosides related to 2-aminoadenosine and isoguanosine: synthesis, deamination and tautomerism
作者:Frank Seela、Kuiying Xu
DOI:10.1039/b708736e
日期:——
than that of the related purines. The pK(a) values indicate that the 7-non-functionalized nucleosides 1a (pK(a) 5.8) and 15 (pK(a) 6.4) are possibly protonated in neutral conditions when incorporated into RNA. The nucleosides 3a-d exist predominantly in the keto (lactam) form with K(TAUT) (keto/enol) values of 400-1200 compared to 10(3)-10(4) for pyrrolo[2,3-d]pyrimidine isoguanosine derivatives 4a-c