New heteroaryl‐substituted o‐divinylbenzenes, 2,2′‐(1,2‐phenylenedivinylene)difuran (9), 2,2′‐(1,2‐phenylenedivinylene)bisbenzobfuran (10), and 2,2′‐(1,2‐phenylenedivinylene)bisnaphtho2,1‐bfuran (11), were prepared and irradiated at various concentrations; intramolecular photocycloaddition and intermolecular 2+2 twofold photoaddition reactions took place to give bicyclo3.2.1octadiene derivatives 12–14 and cyclophane derivatives 15–17, respectively. Compound 11 was the most selective of these o‐divinylbenzenes, which, owing to π–π intra‐ or intermolecular complexation, gave only the exo‐bicyclo3.2.1octadiene derivative 14 at low concentrations, and only the cyclophane derivative 17 at high concentrations. A matter of concentration: The β,β′‐diheteroaryl‐substituted o‐divinylbenzenes 1–3 were irradiated and the photoproducts examined (see scheme): the bisnaphthofuran derivative 3 is the most selective, which, owing to π–π intra‐ or intermolecular complexation, gives only the exo‐bicyclo3.2.1octadiene derivative 4 upon irradiation at low concentrations and only the cyclophane derivative 9 at high concentrations.