title: Synthesis of heterocyclic homotriptycenes.
abstract: A series of novel heterocyclic homotriptycenes bearing furan, thiophene, and pyridine rings, 7a-f, were synthesized by intramolecular dehydration reactions of 10,10-dihetarylmethyl-9,10-dihydroanthracen-9-ols 6a-f. In the presence of acids, the secondary alcohols 6a-f show different reactions which depend on the electron densities of the attached heterocyclic rings. The initially formed carbenium ions react in an electrophilic substitution with electron-rich heterocycles. The formation of a transannular bridge (1,7-elimination) leads to homotriptycenes in high yields. When the heterocyclic ring has a moderate electron density, two competitive reactions exist, which afford 9-monosubstituted anthracenes by 1,4-elimination or 9,10-disubstituted anthracenes by a rearrangement, respectively. Electron-deficient heterocycles undergo a disproportionation to give hydrocarbons and ketones.
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Derong
authors.initials: D
authors.lastname: Cao
authors.forename: Wenjie
authors.initials: W
authors.lastname: Liu
authors.forename: Huanfeng
authors.initials: H
authors.lastname: Jiang
authors.forename: Herbert
authors.initials: H
authors.lastname: Meier
mesh_terms: D001952:Bridged-Ring Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D013237:Stereoisomerism
chemical_list: D001952:Bridged-Ring Compounds; D006571:Heterocyclic Compounds