[2. n](2, 5) Pyridinophanes possessing a cyclobutane ring and dioxaoligomethylene chain as tethers were efficiently prepared by intramolecular [2+ 2] photocycloaddition of vinylpyridine derivatives using a 400-W high-pressure mercury lamp through a Pyrex filter. They were of cis-configuration with respect to the cyclobutane ring, which was proved by the specific methine proton signals at δ 3.95–4.14. If the dioxaoligomethylene chain is short, ...