166166-09-2Relevant academic research and scientific papers
N-Alkenyl Nitrone Dipolar Cycloaddition Routes to Piperidines and Indolizines. Part 6. Allylic Stereocontrol in the Intramolecular Cyclisation of Monosubstituted Nitrones
Collins, Ian,Nadin, Alan,Holmes, Andrew B.,Long, Martin E.,Man, Jocelyn,Baker, Raymond
, p. 2205 - 2216 (2007/10/02)
The intarmolecular, thermal dipolar cycloadditions of the (Z)-N-alk-4-enyl nitrones 18-21, 34 and 36 bearing a single, allylic substituent were investigated.Certain alkoxy substituted nitrones 18-21 showed a remarkable preference for the formation of axially substituted isoxazolidines 22a-24a, whereas the propyl and trifluoromethyl substituted nitrones 35 and 34 gave the equatorially substituted cycloadducts 37 and 36a respectively, consistent with the involvement of 'chair-like' transition states 38.
