ABSOLUTE CONFORMATION AND SUBSTITUENT EFFECTS ON CHIROPTICAL PROPERTIES OF THOXYCARBONYL)-9,10-DIHYDRO-9,10-ETHENOANTHRACENES

Optically active and inactive rotational isomers of ethoxycarbonyl)-9, 10-dihydro-9,10-ethenoanthracene were isolated. The absolute conformat ions of these optically active conformers were determined by correlati ng them with those of camphorsultam amides of hoxycarbonyl)-9,10-dihyd ro-9,10-ethenoanthracenes, the latter being determined by X-ray analys is. From the carboxylic acids, the title compounds, in which the halog en is a chloro, a bromo, or an iodo, were prepared. The CD spectra of the title compounds showed remote substituent effects on the Cotton ef fect at ca. 220 nm.