Synthesis of Cycloprop[b]anthracenes via Trapping of o-Naphthoquinodimethane

Cyclopropb]anthracenes 1, 1a, 1b are prepared in a 3-step synthesis starting from o-di(iodomethyl)benzene. The key step consists of trapping of o-naphthoquinodimethane (9) with 1,2-di- and tetrahalogenocyclopropenes (3, 3a, 4b) .