One pot synthesis of the butenonyl-C-beta-D-glycosides with malononitrile in the presence of K2CO3 in water under mild and green reaction conditions leading to the formation of small library of multifunctional biphenyl methyl-C-beta-D-glycosides in good yields has been reported. The reaction is equally applicable with the substrates having different glycosyl pyranoses and aromatic rings with different substituents. (C) 2010 Elsevier Ltd. All rights reserved.
A novel and efficient direct aldol condensation from ketones and aromatic aldehydes catalyzed by proline–TEA through a new pathway
作者:Jun-feng Wang、Meng Lei、Qin Li、Ze-mei Ge、Xin Wang、Run-tao Li
DOI:10.1016/j.tet.2009.04.052
日期:2009.6
aldol condensation from various ketones and a wide range of aldehydes was catalyzed by l-proline–TEA (triethylamine) in MeOH at room temperature, affording the corresponding (E)-α,β-unsaturated ketones in excellent yields. By using the method, some complicated (E)-α,β-unsaturated ketone C-glycosides were obtained from unmodified ketone C-glycosides and aldehydes. This reaction proceeds through a new
A series of pyranosyl homo-C-nucleosides have been synthesized by reaction of butenonyl C-glycosides (5a-5j, and 8) and cyanoacetamide in presence of t-BuOK followed by further modifications. The reaction proceeds by Michael addition of cyanoacetamide to the butenonyl C-glycosides and subsequent dehydrative cyclization and oxidative aromatization to give glycosylmethyl pyridones (6a-6j, 7a-7j, 9, and