Stereoselective synthesis of 2-azapurine 2′-deoxy-β-D-ribonucleosides by nucleobase-anion glycosylation

✍ Scribed by Kazimierczuk, Zygmunt ;Seela, Frank

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 457 KB
• Volume: 1990
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.1990199001123

✦ Synopsis

Abstract

Nucleobase‐anion glycosylation of 6‐(methylthio)‐2‐azapurine (1) with 2‐deoxy‐3,5‐di‐O‐(p‐toluoyl)‐α‐D‐erythro‐pentofuranosyl chloride (2) yields the 2′‐deoxy‐β‐D‐ribofuranosides 3–5 stereoselectively. The distribution of regioisomers is as follows: N‐9 (32%); N‐2 (30%), and N‐7 (7%) together with a minor amount of an unidentified labile glycosylation product. The anomeric configuration and the site of glycosylation have been assigned on the basis of the ^1^H‐NOE difference spectral data in combination with gated‐decoupled ^13^C‐NMR and selective INEPT spectroscopy. The regioisomeric 6‐methylthio nucleosides have been converted into 6‐substituted derivatives of biological interest including 2′‐deoxy‐2‐azaadenosine (8). Compound 8 is a substrate of adenosine deaminase.