96039-13-3Relevant academic research and scientific papers
Cascade oxime formation, cyclization to a nitrone, and intermolecular dipolar cycloaddition
Furnival, Rachel C.,Saruengkhanphasit, Rungroj,Holberry, Heather E.,Shewring, Jonathan R.,Guerrand, Hélène D. S.,Adams, Harry,Coldham, Iain
, p. 10953 - 10962 (2016)
Simple haloaldehydes, including enolisable aldehydes, were found to be suitable for the formation of cyclic products by cascade (domino) condensation, cyclisation, dipolar cycloaddition chemistry. This multi-component reaction approach to heterocyclic compounds was explored by using hydroxylamine, a selection of aldehydes, and a selection of activated dipolarophiles. Initial condensation gives intermediate oximes that undergo cyclisation with displacement of halide to give intermediate nitrones; these nitrones undergo in situ intermolecular dipolar cycloaddition reactions to give isoxazolidines. The cycloadducts from using dimethyl fumarate were treated with zinc/acetic acid to give lactam products and this provides an easy way to prepare pyrrolizinones, indolizinones, and pyrrolo[2,1-a]isoquinolinones. The chemistry is illustrated with a very short synthesis of the pyrrolizidine alkaloid macronecine and a formal synthesis of petasinecine.
