Regioselective Mannich-type C-nucleosidations of pyrroline derivatives 3 and 8 with 7-carba-purines and 4-aminopyrimidines occur under mild conditions to afford C(8)- and C(5)-azanucleosides, respectively.
C-Nucleosidation with cyclic iminium salts occurring under mild reaction conditions and affording C-nucleosides that are isosteric with N-nucleosides of natural purines is shown to be a consistent property of the entire family of 2,6-(oxo or amino)-disubstituted 5,8-diaza-7,9-dicarba-purines.
C-Nucleosidations with 2,6-Diamino-5,8-diaza-7,9-dicarba-purine<sup>1</sup>
Endocyclic iminium ions derived from (L)-4-amino-threose derivatives smoothly react with 2,6-diamino-5,8-diaza-7,9-dicarba-purine to give corresponding C(9)-nucleosides in high yields.
Synthesis of (3S,4S)-3,4-Dihydroxyprolines from L-Tartaric Acid.
作者:Yasushi ARAKAWA、Shigeyuki YOSHIFUJI
DOI:10.1248/cpb.39.2219
日期:——
Natural (2S, 3S, 4S)-3, 4-dihydroxyproline (1) and the new (2R, 3S, 4S)-isomer (7) have been synthesized from L-tartaric acid via cyanosilylation of the cyclic Schiff base.