Dibenz [a, h] anthracene 3, 4-oxide 5ARS, synthesised from the enantiopure dibromoMTPA precursor 9ARRS*, was found to have totally racemized and to be accompanied by benz [5, 6] anthra [1, 2-b] oxepine 11A. Phenanthrene 3, 4-oxide 5BRS, obtained from the enantiopure bacterial metabolite cis-3, 4-dihydroxy-3, 4-dihydrophenanthrene 12B by a modified synthetic approach involving the chlorohydrin ester 16B, was observed to ...