Tetracyclic 1,5-methanoazocino[4,3-b]indole (2) was achieved via a new synthetic approach for the synthesis of related strychnos alkaloids. These products embody the ABCD-ring system associated with the title alkaloids, as well as a one-pot construction of the ABCD ring system using tetrachloro-1,4-benzoquinone and tetrafluoro-1,4-benzoquinone, were involved as key steps. Also, the DFT-based quantum chemical calculations have been performed to evaluate the structural, electronic, and spectroscopic properties of the compound. PES (potential energy surface) scan revealed three stable conformers of the compound. The calculated FT-IR and NMR spectral data were compared with the corresponding observed values for the most stable conformer of the compound. Frontier Molecular Orbital analysis has revealed the chemical reactivity tendency and sites of the compound.