Synthesis of novel 3,4-fused pyrazolidinone γ-lactam bicyclic moieties from 2,3-dioxo-4-carboxy-5-(substituted)pyrrolidines

Özet

A new pathway for the synthesis ofnovel 3,4-fused pyrazolidinone γ-lactam (4) starting from 2,3-dioxo-4-carboxy-5-(substituted)pyrrolidines (1) was developed. The key synthetic strategy involved hydrazonation of the precursor 1followed by subsequent reduction reaction of theenamino ester 2and intramolecular cyclization reaction to furnish the unprecedented 3,4-fused pyrazolidinone γ-lactam (4) in reasonable yield.The structureswere confirmed by spectroscopic methods and chemical transformation.