Photochemical Approach to New Polycyclic Substrates Suitable for Further Photocatalytic Functionalization

New polycyclic compounds are synthesized by photocycloaddition reactions of methoxy, methyl or phenyl substituted butadiene derivatives 11−14. Mono- and dimethoxy butadiene derivatives 11 and 12 undergo intramolecular [2+2] photocycloaddition giving benzobicyclo[3.2.1]octadiene structures (endo-15, endo,trans-17) as main products. As minor photoproducts tricyclic compounds endo-16 and endo,trans-18 are isolated, respectively, formed by [4+2] photoinduced cycloaddition of the starting molecules. The reaction of compounds 13 and 14 is more selective and only benzobicy-clo[3.2.1]octadienes endo,endo-19 and endo,endo-20 are formed, respectively. New bicy-clo[3.2.1]octadienes with isolated double bond can be suitable substrates for further efficient photo-catalytic oxygenations in course of new functionalized polycycles, potentially new biologically active compounds