Absolute Conformation and Chiroptical Properties. VI. 2, 2', 3, 3'-Tetramethoxy-9, 9'-bitriptycyl: A Stereochemical Analog of 1, 2-Disubstituted Ethane with Identical Substituents ~(1, 2))

摘要

The title compound was prepared by addition of 4, 5-dimethoxybenzyne to 9, 9'-bianthryl. The rotational isomers, ap and ± sc, were separated by HPLC. The ± sc isomers were treated with sodium ethanethiolate to produce 3, 3'-dihydroxy-2, 2'-dimethoxy-9, 9'-bitriptycyl, which was converted to the ester of (1S, 5R, 7R)-4-[(2-carboxy) benzoyl]-3-thia-4-azatricyclo [5. 2. 1. 0~(1, 5)] decane 3, 3-dioxide. The resulting diastereomers were separated by HPLC. The isomers were hydrolyzed and methylated with dimethyl sulfate to yield optically active 2, 2', 3, 3'-tetramethoxy-9, 9'-bitriptycyl. The absolute conformation of the tetramethoxy compound was determined by X-ray structure analysis of 3'-ester of (1S, 5R, 7R)-4-(2-carboxybenzoyl)-3-thia-4-azatricyclo [5. 2. 1. 0~(1, 5)] decane 3, 3-dioxide derived from 3-hydroxy-2, 2', 3'-trimethoxy-9, 9'-bitriptycyl, followed by hydrolysis and then methylation. The CD spectrum of Msc-2, 2', 3, 3'-tetramethoxy-9, 9'-bitriptycyl is reported.