The core structure 4-oxo-4H-quinolizine-2-carboxylate has been successfully synthesized via a one pot Stobbe condensation/cyclization reaction sequence starting from pyridine-2-carbaldehyde in the presence of such a strong base as potassium tert-butylate. From this core structure, a new derivative benzoyloxiran-4H-quinolizin-4-one was effectively prepared. The structure of this new compound was fully determined based on MS, ¹H-NMR, ¹³C‑NMR, COSY, DEPT, HMBC and HSQC spectrometry methods. Bioactivity evaluation results showed that the prepared derivative possessed moderate activity against H1N1 virus but as good cytotoxicity as the positive control Tamixifen toward the MCF-7 cell lines.