Syntheses and Absolute Stereochemistry of Chiral 9,10-Dihydro-9,10-ethanoanthracenes and their Tricarbonylchromium Complexes

Article abstract of DOI:10.1007/BF00814140

Several chiral mono- and disubstituted 9,10-dihydro-9,10-ethanoanthracenes have been prepared from the corresponding anthracenes.Most of them were separated into enantiomers by chromatography on cellulose triacetate (CTA) and their absolute chiralities established by chiroptical comparison (via their CD spectra) with key compounds of known configuration.From the laevorotatory 1,5-dibromo derivative 16 the dextrorotatory dideuterio hydrocarbon (+)(9S,10S)-20 was obtained.Complexation of 2,6-dimethyl 9,10-dihydro-9,10-ethanoanthracene (+)-25, obtained by enantioselective chromatography on CTA , with Cr(CO)6 afforded two mono tricarbonylchromium complexes as well as the bis-exo,endo-complex (+)-28.Configurational assignments (exo,endo) are based on the absorption patterns of the bridge protons in the 1H NMR spectra. Keywords: (+)-1,5-Dideuterio-9,10-dihydro-9,10-ethanoanthracene; Enantioselective chromatography on CTA; Circular dichroism; Configurational correlation; Tricarbonylchromium complexes.