Symmetry-modified conformational mapping and classification of the medium rings from crystallographic data. III. endo-unsaturated seven-membered rings

Crystallographic results retrieved from the Cambridge Structural Database (CSD) have been used to perform systematic conformational analyses for cycloheptene, cyclohepta-1,3-diene, cyclohepta-1,4diene and cyclohepta-1,3,5-triene. Conformational mappings based on symmetry-adapted deformation coordinates show that, with the exception of cycloheptene (for which a C4 conformation is dominant), all conformations adopted by these unsaturated systems are intermediate between chair-like and boat-like forms