Gao, Chunmei Cao, Derong Xu, Sheyang Meier, Herbert Acid-Catalyzed Cyclization of Anthracenol Derivatives to Homotriptycenes 10-Benzyl-9,10-dihydroanthracen-9-ols, having high electron densities in the benzene ring, exhibit in the presence of acid a transannular ring closure to the corresponding homotriptycenes in almost quantitative yields. Since the starting compounds are easily accessible from 9(10<i>H</i>)-anthracenone, this process represents the most facile route to such pentacyclic systems. An electron-releasing methoxy group enables the intramolecular electrophilic substitution in its para position. In the absence of such an activation, a number of alternative processes can occur, namely the acid-catalyzed dehydration to anthracene derivatives with (R ≠ H) or without (R = H) rearrangement or a disproportionation reaction of the secondary alcohol to the corresponding ketone and hydrocarbon. exhibit;benzene ring;Cyclization;dehydration;homotriptycene;acid;density;presence;alternative processes;Anthracenol Derivatives;absence;hydrocarbon;Benzyl;pentacyclic systems;activation;methoxy;anthracene derivatives;disproportionation reaction;compound;intramolecular electrophilic substitution;anthracenone;para position;yield;electron densities;ketone;Homotriptycene;rearrangement;transannular ring closure 2006-04-14
    https://acs.figshare.com/articles/journal_contribution/Acid_Catalyzed_Cyclization_of_Anthracenol_Derivatives_to_Homotriptycenes/3227365
10.1021/jo0526791.s003