Synthesis of triphenylene 1,2-oxide (1,2-epoxy-1,2-dihydrophenylene) and absolute configuration of the trans-1,2-dihydro diol metabolite of triphenylene. Crystal structure of (–)-(1R,2R)-trans-2-bromo-1-menthylxyacetoxy-1,2,3,4-tetrahydrotriphenylene

Abstract

The synthesis of triphenylene 1,2-oxide (1,2-epoxy-l,2-dihydrotriphenylene)(2) from both racemic and optically pure precursors is reported. Racemic triphenylene 1,2-oxide (2) was obtained in each case, in accord with PMO calculations which predict rapid racemization. Liver microsomal metabolism of both triphenylene (1) and racemic triphenylene 1,2-oxide (2) yielded predominantly the (–)-enantiomer (92 and 85%, respectively) of the trans-dihydro diol (5). The 1R5,2R configuration for (–)-(5) has been established by preparative h.p.l.c. separation of the dimenthyloxyacetate diastereoisomers of the dihydro diol (5) and stereochemical correlation to (–)-(1R,2R)-trans-2-bromo-1-menthyloxyacetoxy-1,2,3,4-tetrahydrotriphenylene (9A) whose absolute configuration has been assigned by X-ray crystallographic analysis.