Intra‐ and intermolecular <i>hetero</i> Diels‐Alder Reactions. XIX. Stereoselective synthesis of five‐ and seven‐membered annulated ring systems by intramolecular <i>hetero</i> Diels‐Alder Reaction

Abstract

Abstract The intramolecular hetero Diels‐Alder reaction of the benzylidene‐ and (pyrrolylmethylene)pyrazolones 8 and 12 , which have been obtained by Knoevenagel condensation of 7 with the aldehydes 6 and 11 , respectively, proceeds stereoselectively to give the cis ‐fused heterocycles 13 and 15 in high yields.