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Pyrazolo[3,4‐ d ]pyrimidine 2′ ‐Deoxy‐ and 2′,3′ ‐Dideoxyribonucleosides: Studies on the glycosylation of 4‐methoxypyrazolo[3,4‐ d ]pyrimidine
Author(s) -
Seela Frank,
Winter Holger,
Möller Marianne
Publication year - 1993
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19930760405
Subject(s) - chemistry , pyrimidine , anomer , glycosylation , yield (engineering) , stereochemistry , nucleotide , biochemistry , materials science , metallurgy , gene
The glycosylation of the 4‐methoxypyrazolo[3,4‐ d ]pyrimidine ( 5 ) anion with 1‐halo‐2‐deoxyribose 6 in MeCN/TDA‐1 gives N 2 ‐deoxynucleoside 9 (29%) together with N 1 ‐isomer 7 (48%) and its anomer 8 (6%) [7]. The α‐ D ‐anomer 8 is not formed and the yield of the ß‐ D ‐anomer 7 increased to 62% when dimethoyethane is used as solvent and [18]crown‐6 as catalyst. Employing 1‐halo‐2,3‐dideoxyribose 10 instead of halogenose 6 , the 2′,3′ ‐didexoynucleosides 12 and 14 were formed which desilylated (→ 1b and 2b ) and converted into the ddI and ddA derivatives 3b (c 7 z 8 I dd ), 15b (c 7 z 8 A dd ), and 17 (c 7 z 8 A′ dd ). Contrary to 7‐deazapurine nucleotides, the triphosphates of 3b and 15b showed on appreciable activity against HIV‐reverse transcriptase.