Abstract The Bamford-Stevens reaction of benzaldehyde tosylhydrazone (I) was carried out in the presence of polynuclear aromatics—naphthalene, phenanthrene, anthracene or acridine. Products isolated were norcaradiene derivatives with exo -phenyl group (II, V, VII) and/or ring-benzylated compounds. In addition, anthracene gave a meso -bridged 1,4-adduct (VIII) of phenylcarbene. Diphenylcarbene as produced by the thermal decomposition of diphenyldiazomethane was shown to attack anthracene at the 1,2-position to afford a norcaradiene (X).