Macrocyclic compounds. Part XII. cis–trans Equilibria in non-conjugated cycloalkadienes

Abstract

The thermodynamic equilibria between the trans,trans-, cis,trans-, and cis,cis-isomers of symmetrical cycloalkadienes (C₁₀–C₂₄) were determined at 25 and 75° by irradiation in the presence of diphenyl sulphide or disulphide. The preferences for certain isomers are explained on a conformational basis. Using acetophenone as a photosensitiser, the photostationary states were also established; they often approximate to the thermodynamic equilibria.