Intramolecular Diels–Alder reaction with furans: effect of the substitution pattern reinvestigated

Abstract
Intramolecular Diels–Alder reactions occurred smoothly when N-(α-cyanofurfuryl)arylamines 2a–g and N-furfurylarylamines 7a–d were treated with maleic anhydride and fumaroyl chloridetriethylamine respectively, to afford the corresponding cycloadducts 4 and 10 in good yields. Electron-withdrawing groups and the cyano group inhibited the IMDA reaction when a less activated dienophile was employed. The structures of these IMDA products were fully characterised on the basis of spectral results and elemental analyses.