stereoconvergent 1,3-dipolar cycloaddition of nitrileoxides and nitrile imines with E/Z isomeric mixture of electron-deficient olefins is reported, delivering isoxazolines and pyrazolines bearing two vicinal stereogenic tertiary and trifluoromethylated quaternary carbon centers with perfect regio- and diastereoselectivities. The possibility of concerted cycloaddition/epimerization sequence under basic
oxide with allyl alcohol followed by intramolecular 1,3-diploar cycloaddition reaction of nitrile imine with carbonyl group. All the newly synthesized compounds were screened for their anti-inflammatory and analgesic activities. Among the list of compounds (7a–k) studied, 7d, 7g, 7j, and 7k exhibited excellent activity comparable to ibuprofen and aspirin at the similar dosages.
A New Method for the Generation of Nitrile Oxides and Its Application to the Synthesis of 2-Isoxazolines
作者:Alfred Hassner、K. M. Lokanatha Rai
DOI:10.1055/s-1989-27152
日期:——
Reaction of aldoximes with choramine-T leads to formation of nitrile oxides which can react in situ intra- or intermolecularly with olefinic compounds to produce isoxazolines in good yield.
Lokanatha Rai; Hassner, Alfred, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1997, vol. 36, # 3, p. 242 - 245
作者:Lokanatha Rai、Hassner, Alfred
DOI:——
日期:——
Sugar-based ethenyl ethers: stereoselective dipolar cycloadditions of nitrile oxides
作者:Matthieu Desroses、Florence Chéry、Arnaud Tatibouët、Ottorino De Lucchi、Patrick Rollin
DOI:10.1016/s0957-4166(02)00709-7
日期:2002.11
Selected sugar-based ethenyl ethers have been employed in 1,3-dipolar cycloaddition with nitrite oxides. In the D-fructo series, high diastercoselectivity was observed as compared with the 3-epimeriC D-psico series. (C) 2002 Elsevier Science Ltd. All rights reserved.