The synthesis and conformationl studies of 9-monosubstituted-10-Chloro-9Hcyclohepta[ def]phenanthrene

Some derivatives of 9-monosubstituted-10-Chloro-9H-cyclohepta[def]phenanthrene have been synthesized in a nucleophlic addition to cyclopropyl ring in 9, 9-dichloro-9H-cyclopropa[e]pyrene. Quantum mechanic calculations indicate that conformation of cycloheptatriene ring in these derivatives has a nearly flatted boat conformation. In this form the C-9 constituent can be oriented in pseudo equatorial (e´) and pseudo axial (a´) directions. The fast interchange process of a´- e´ involves ring inversion of the cycloheptatriene moiety in low level of energy, so in room temperature the conformational diastereomers can not determined by 1H-NMR.