Synthesis of Dibenz[a,h]anthracenes by Pd-Catalyzed Intramolecular Double-cyclization of (Z,Z)-p-Styrylstilbenes

Dibenz[a,h]anthracene (1a) and its dimethoxy derivatives 1b and 1c were synthesized by the Pd-catalyzed intramolecular double-cyclization of the corresponding (Z,Z)-p-styrylstilbene derivatives 2-5, which were readily prepared by the Wittig reaction. The optical properties of the dibenz[a,h]anthracenes 1a-1c are also presented.