Inclusion and Reaction Chemistry of Two Anthracene-Appended γ-Cyclodextrins

Summary

The anthracene moieties of regioisomers of 6A,6X-bis(anthracene-9-carbonyl)-γ-cyclodextrins undergo photodimerization, affording a trans photodimer for AC, AD, and AE isomers and a cis photodimer for the AB isomer. The photodimers of the AD and AE isomers were stable, but those of AB and AC were unstable, returning to the original anthracene monomers. The dissociation of the photodimers was suggested to be due to the inherent instability of the cis photodimer of the AB isomer and the strain-rich nature of the trans photodimer of the AC isomer. The photodimerization followed by hydrolysis of 6A,6X-bis-(anthracene-1-carbonyl)-γ-cyclodextrins afforded four photodimers of 1-anthracenecarboxylic acid, the relative yields of the photodimers being controlled by the locations of the anthracene moieties in the regioisomers. These results demonstrate that the γ-cyclodextrin template method is useful to make chemical reactions proceed stereoselectively as well as to produce new photochrome systems.