Calcium Carbide as Acetylene Source in Cascade Assemblies of Hydroxypyrrolines and 3H‐Pyrroles from Ketoximes

Abstract Two types of rare five‐membered aza ‐heterocycles, namely 3,3‐disubstituted‐3 H ‐pyrroles and 5‐hydroxypyrrolines, were synthesized from calcium carbide and available sec ‐alkyl (het)aryl ketoximes in the MOH/DMSO (M=Na, K) superbase systems. In contrast to the known procedures implemented with acetylene gas, the modified method is expedient and much safer that makes these intriguing aza ‐heterocycles accessible for any laboratory without facilities working with acetylene gas.