Regioselectivity of the Mannich Reaction on Pyrrolo[2,3-d]pyrimidine Nucleosides Related to 7-Deaza-2'-deoxyadenosine or 7-Deaza-2'-deoxyguanosine
作者:Frank Seela
DOI:10.1055/s-1997-1305
日期:1997.9
Mannich reactions were performed on 7-deazapurine 2'-deoxyribonucleosides and the regioselectivity was studied. 7-Deaza-2'-dioxyadenosine (2'-deoxytubercidin, 4a) furnished the 7-substituted Mannich base 5a. The side chain was introduced in the 8-position when 7-deaza-2'-deoxyguanosine was used (Mannich base 7a). The regioselectivity changed back from position 8 to 7 when the reaction was performed on 4-methoxy-2-methylthio-7H-pyrrolo[2,3-d]pyrimidine 2'-deoxyribonucleoside (12). Thus a 7-substituted Mannich product of 7-deaza-2'-deoxyguanosine could be obtained after demethylation and oxidation of the methylthio group followed by displacement of the oxidized 2-substituent with ammonia.