Facile synthesis of functionalized 6-cyano-2-oxa-7-azabicyclo[4.1.0]hept-3-en-1-yl acetates: a catalyst free approach to access the pyran fused 2-acetoxy-NH-aziridines

Novel 6-cyano-2-oxa-7-azabicyclo[4.1.0] hept-3-en-1-yl acetate scaffolds were synthesized directly from 2-amino-3-cyano-4-H-pyrans as well as 2-amino-3-cyano-spiropyrans using iodobenzene diacetate (PIDA) as oxidant at room temperature in the absence of any catalyst. Essentially, the enamine fragment of the reactants reacts with PIDA, which makes this reaction a new way to synthesize pyran fused 2-acetoxy- NH-aziridines. These remarkably stable pyran fused 2-acetoxy-NH-aziridines can be used in SAR studies in pharmaceutical and medicinal chemistry. Ready availability of the starting materials, operational simplicity, absence of metal catalyst, mild reaction conditions, and simple workup procedure are the other significant features of this reaction.