ABSOLUTE CONFORMATION AND SUBSTITUENT EFFECTS ON CHIROPTICAL PROPERTIES OF 9-(2-HALO-1,1-DIMETHYLETHYL)-11,12-BIS(METHOXYCARBONYL)-9,10-DIHYDRO-9,10- ETHENOANTHRACENES

摘要

Optically active and inactive rotational isomers of 9-(1,1-dimethyl-3-butenyl)-11,12-bis(methoxycarbonyl)-9,10-dihydro-9,10-et henoanthracene were isolated. The absolute conformations of these optically active conformers were determined by correlating them with those of camphorsultam amides of 9-(2-carboxy-1,1-dimethylethyl)-11,12-bis(methoxycarbonyl)-9,10-dihydro-9, 10-ethenoanthracenes, the latter being determined by X-ray analysis. From the carboxylic acids, the title compounds, in which the halogen is a chloro, a bromo, or an iodo, were prepared. The CD spectra of the title compounds showed remote substituent effects on the Cotton effect at ca. 220 nm.