Bull. SOC. Chim. Belg., 58, pp. 87-102, 1949 I ... Syntheses dans le domaine des hydrocarbures canchrigihes ... SUMMARY. - 9.10-dimethyl-1.2.3.4-dibrnzanthraccne (IIIb) and 9.10-dimethyl-1.2.7.8-dibenzanthracene (IVb) have been prepared. Attempts to synthcsise 6.8-dimethyl-1.2.6.7-dibenzphenanthrene (Vb) have been unsuccessful. In particular, the corresponding decahydro- derivative (XII) could not be fully dehydrogenated. ... De nombreux travaux ...