The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 16. [1]benzothieno[2′,3′:4,5]thieno[2,3‐c]quinoline and [1]benzothieno[2′,3′:4,5]thieno[2,3‐c]naphtho[1,2‐f]quinoline

The synthesis of two previously unknown polycyclic heterocyclic ring systems via photocyclization is described. The unequivocal assignment of their proton and carbon spectra was achieved by utilizing two‐dimensional nmr techniques.