The syntheses of three new benz-annelated derivatives of aceanthrylene and acephenanthrylene are reported. These systems are of interest in studies on mechanisms of bioactivation and structure-activity correlations because of their predicted high level of biological activity. Of the three isomers, benz(d)aceanthrylene has been synthesized by two routes involving Friedel-Crafts acylations of 1,2,3,4-tetrahydronaphthacene with chloroacetyl chloride or oxalyl chloride as the key step. The cyclic ketone product from each route has been successfully elaborated. Synthesis of benz(k)aceanthrylene involves preparation of acenaphthene-3,4-di-carboxylic anthdride and its smooth conversion. A straightforward and high-yield synthesis of benz(j)acephenanthrylene is described utilizing a Robinson annelation reaction of methyl vinyl ketone with a previously reported ketonic precursor of acephenanthrylene. (Copyright (c) 1987 American Chemical Society.)