Laser-induced precipitation and crystal growth were observed by an irradiation of benzophenone in an ethanol and water mixed solvent. The crystal was composed of benzopinacol produced from excited benzophenone through a benzophenone ketyl radical. Polyhedral, skeletal, and dendrite morphologies of benzopinacol were controlled by laser energy. This is the first example of a photochemical morphology control of a crystal.

Two-directional annulation of dibromoisobenzofuran, a formal equivalent to didehydroisobenzofuran, was developed. Importantly, selective bromine-lithium exchange allows the tandem generation of benzynes and dual cycloadditions with two different arynophiles. Also described is the application to the synthesis of a substituted pentacene.

Stereoselective [4+2] cycloadditions of 1,4-dihydro-1,4-epoxynaphthalene and isobenzofuran were described. Among several possibilities, syn-exo and/or anti-endo isomers were selectively produced depending on the substitution pattern of the reactants. Importantly, the syn-exo isomer underwent acid promoted aromatization, affording the corresponding tetracene. These findings enabled us to prepare a substituted pentacene with electron withdrawing groups.