113058-38-1

The synthesis and spectral properties of 1α-acetoxy-2β,4α-dibromo-, 4α-acetoxy-1α,3β-dibromo-, 2β,4α-dibromo-1α-trifluoroacetoxy- and 1α,3β-dibromo-4α-trifluoroacetoxy-1,2,3,4-tetrahydrodibenzanthracene are described.The reaction of the two dibromo acetates with anhydrous sodium methoxide produces labile dibenzanthracene 1,2-oxide and dibenzanthracene 3,4-oxide concomitantly with relatively major amounts of comparatively stable benzanthraoxepine or anthraoxepine, respectively.No improvement in the formation of the two arene oxides in which the ester group is much more labile than that in the dibromo acetates.Under milder reaction conditions, the 2β,4α-dibromo-1α-trifluoroacetate is hydrolysed to the 2β,4α-dibromo-1α-alcohol which, on subsequent treatment with sodium methoxide, also produces benzanthraoxepine as one of the major products.These studies show for the first time that the use of dibromoesters with a labile ester group has no advantage in the synthesis of the two aforementioned arene oxides because dibromo alcohols produced in these reactions are the intermediates for the formation not only of arene oxides but also of oxepines as well.

The isomeric benzo-ring cis-dihydrodiols and phenols of dibenzanthracene (DBA) have been synthesized.The appropiate dihydro-DBA was treated with osmium tetraoxide to produce the corresponding cis-tetrahydrodiols of DBA.These cis-tetrah