Regioselective Glycosylation: Synthesis of <i>α</i>-Indoline Nucleosides
作者:Kenneth L. Brown、Tilak Chandra、Shawn Zou、Edward J. Valente
DOI:10.1081/ncn-200067398
日期:2005.7.1
Novel indoline ribonucleosides with the alpha-N-glycoside configuration are synthesized with very high regioselectivily in 90-96% yield, using TMS protected indolines and 2,3-O-(1-methylethylidene)-5-O-(triphenylmethyl)-alpha/beta-D-ribofuranose. The structures of these ribonucleosides were elucidated with X-ray crystallography as well as 2D (NOESY COSY and HMQC) NMR spectroscopy.
Deprotection of α-imidazole/benzimidazole ribonucleosides by catalytic carbon tetrabromide initiated photolysis
作者:Tilak Chandra、Kenneth L. Brown
DOI:10.1016/j.tetlet.2005.09.180
日期:2005.12
Several protected benzimidazole and imidazole alpha-ribonucleosides were deprotected in excellent yield Lit ambient temperature using CBr4 initiated photolysis in methanol at ambient temperature. No selectivity was observed and both trityl and isopropylidene groups were deprotected Under the reaction conditions. (c) 2005 Elsevier Ltd. All rights reserved.
Chemoselective Deprotection of α-Indole and Imidazole Ribonucleosides
作者:Tilak Chandra、Kenneth L. Brown
DOI:10.1080/15257770601052216
日期:2007.1
A series of 2 ',3 '-isopropylidene and 5 '-trityl-protected alpha-indole and alpha/beta-benzimidazole and imidazole ribonucleosides were deprotected with different acids. Selectivity was achieved for 5 '-versus 2 ',3 '- deprotection by using formic acid in the alpha-indole ribonucleoside series. Treatment of alpha-indole ribonucleosides with a mixture of formic acid and ether at room temperature afforded