5,6,7,8-Tetrahydro-5,5,8,8-tetramethyl-2-bromoanthracene (I) was lithiated with tert-butyllithium in THF at -78 C, and subsequently condensed with dimethylformamide to provide, after aqueous workup, aldehyde (II). This was condensed with butenoate (III) in the presence of potassium tert-butoxide in cold THF to give intermediate (IV), which by final addition of water experienced hydrolysis to the target dicarboxylic acid.