Synthesis of 6-Substituted Purine N7-(2-Deoxy-β-D-Ribonucleosides) via Anion Glycosylation and Anomerization During the N7/N9-Glycosyl Transfer
摘要:
The synthesis of the 7-(2-deoxy-beta-D-erythro-pentofuranosyl) adenine (Ib) as well as the corresponding hypoxanthine- and purine nucleosides 3 and 4 is described employing the stereoselective nucleobase anion glycosylation. The N-7/N-9- isomer distribution of the 6-substituted purine (2-deoxyribonucleosides) depends on 6-substituent. Glycosyl transfer of 8a resulted in anomerization and yielded a mixture of the anomeric 6-methoxypurine N-9-(2-deoxy-D-ribonucleosides) 7a/7d. The preferred glycosylic bond conformation of purine N-7-(2-deoxyribonucleosides) is anti.
1,1,1,3,3,3-Hexafluoro-2-propanol for the removal of the 4,4′-DimethoxytrityI protecting group from the 5′-hydroxyl of acid-sensitive nucleosides and nucleotides
作者:Nelson J. Leonard、Neelima
DOI:10.1016/0040-4039(95)01673-6
日期:1995.10
1,1,1,3,3,3-Hexafluoro-2-propanol is introduced as a suitable reagent and solvent for the detritylution of 5′-O-(4,4′-dimethoxytrityl)-nucleosides and -deoxynucleosides, especially those that are susceptible to N-glycosyl cleavage under more strongly acidic conditions.
N7-DNA: Base-Pairing Properties ofN7-(2′-Deoxy-β-D-erythro-pentofuranosyl)-Substituted Adenine, Hypoxanthine, and Guanine in Duplexes with Parallel Chain Orientation