| Abstract: | A new short‐step synthesis of 8a‐azonia6]helicene (1) and the novel dithieno derivatives ( 2 and 3 ) is described. Double photocyclization of 2,8‐distyrylquinolizinium salt (8) gave 1 in 35% yield. Similarly, 2,8‐bis2‐(2‐thienyl)vinyl]‐ and 2,8‐bis2‐(3‐thienyl)vinyl]‐quinolizinium salts ( 9 and 10 ) afforded new azonia6]helicenes containing two thiophene rings at the ends of helix, that is 7a‐azonia‐3,12‐dithia6]helicene (2) and 7a‐azonia‐1,14‐dithia6]helicene (3) , in 43 and 35% yields, respectively. The total assignment of their 1H‐ and 13C‐nmr spectra was performed by utilizing two‐dimensional and NOE nmr spectroscopic methods. |
