treatment of 7,12-benz [ a ] anthraquinone ( 2 ) with methylmagnesium iodide or methyllithium yields mixtures of cis- and trans-7,12-dihydro-7,12-dihydroxy-7,12-dimethylbenz [ a ] anthracenes ( 3a , b ) , in which the ratio of cis to trans lies in the 3 -- 4:1 region .
C0003174
anthraquinone
C0003163
anthracenes