(C-13)-SUBSTITUTED ERYTHRONUCLEOSIDES - SYNTHESIS AND CONFORMATIONAL-ANALYSIS BY H-1 AND C-13 NMR-SPECTROSCOPY

被引:29
作者
KLINE, PC [1 ]
SERIANNI, AS [1 ]
机构
[1] UNIV NOTRE DAME,DEPT CHEM & BIOCHEM,NOTRE DAME,IN 46556
关键词
D O I
10.1021/jo00032a032
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
The erythronucleosides, 9-beta-D-erythrofuranosyladenine (1b), 1-beta-D-erythrofuranosylcytosine (2b), 9-beta-D-erythrofuranosylguanine (3b), and 1-beta-D-erythrofuranosyluracil (4b), were synthesized with and without C-13-substitution at C1' of the furanose ring. 75-MHz C-13 and 620-MHz H-1 NMR spectra of 1-4b were interpreted, in the latter case with the assistance of spectral simulation, and H-1-H-1, C-13-H-1, and C-13-C-13 spin couplings were used to assess furanose conformation. 3J(HH) data in (H2O)-H-2 were treated by computer to determine the preferred north and south conformers, their puckering amplitudes, and their mole fractions in solution, and J(CH) data were used to complement this analysis. A similar treatment of spin coupling data for the corresponding ribonucleosides 1-4a was also conducted to permit a comparison of furanose conformations in both series of compounds. Results show that the removal of the exocyclic hydroxymethyl group from 1-4a, giving 1-4b, significantly enhances the proportion of south conformers in aqueous ((H2O)-H-2) solution.
引用
收藏
页码:1772 / 1777
页数:6
相关论文
共 35 条