Unexpected Anomeric Selectivity of a 1-<i>C</i>-Arylglycal Donor in Kdo Glycoside Synthesis
作者:Yuxin Qian、Jianhao Feng、Masood Parvez、Chang-Chun Ling
DOI:10.1021/jo201531j
日期:2012.1.6
A novel class of 1-C-arylglycals was developed and subjected to N-iodosuccinimide-mediated glycosylations with alcohols. Unexpectedly, all reactions provided 2-iodo-beta-D-ketopyranosides in high yields and excellent stereoselectivity. After removal of the 2-iodide by radical conditions, the aryl group was smoothly oxidized to provide the corresponding beta-Kdo glycosides. A mechanism for the stereoselective formation of beta-D-ketopyranosides was proposed, which was supported by evidence from X-ray crystallography.