STEREOSELECTIVE SYNTHESIS OF PUTATIVE DIOL EPOXIDE METABOLITES OF 4H-CYCLOPENTA[DEF]CHRYSENE

Syntheses of the anti-diol epoxide derivatives of the methylene-bridged polycyclic aromatic hydrocarbon 4H-cyclopenta[def]chrysene in both the bridge- and non-bridge-substituted rings (2 and 3) and the syn-diol epoxide derivative in the non-bridge-substituted ring (14) are described. These compounds are suspected to be active carcinogenic metabolites of the parent hydrocarbon. They are the first examples of the diol epoxide derivatives of a nonalternant methylene-bridged tumorigenic hydrocarbon to be synthesized, The bridge-substituted anti-diol epoxide derivative 2 is relatively stable, despite its relatively strained structure, and it possesses a unique ''locked'' structure which severely restricts conformational interconversion.