US EPA

5151671 

Journal Article 

SYNTHESIS OF ANTI-DIOL AND SYN-DIOL EPOXIDES OF TRANS-4,5-DIHYDRO-4,5-DIHYDROXYBENZO[J]FLUORANTHENE AND TRANS-9,10-DIHYDRO-9,10-DIHYDROXYBENZO[J]FLUORANTHENE 

He, ZM; Rice, JE; Lavoie, EJ 

1992 

Yes 

Journal of Organic Chemistry
ISSN: 0022-3263
EISSN: 1520-6904 

57 

6 

1784-1789 

10.1021/jo00032a034 

WOS:A1992HJ48600034 

https://pubs.acs.org/doi/abs/10.1021/jo00032a034
Exit
 

The preparation of diastereomeric anti- and syn-epoxides of benzo[j]fluoranthene (BjF) 4,5- and 9,10-dihydrodiols is described. The anti-diol epoxides were prepared from the corresponding dihydrodiols by epoxidation with m-chloroperoxybenzoic acid. The isomeric syn-diol epoxides were synthesized by base-catalyzed (Amberlyte IRA-400) cyclization of the bromo triol derivatives which in turn were prepared from the respective dihydrodiols by treatment with N-bromoacetamide in aqueous THF. New methods were employed for the preparation of 4- and 10-hydroxyBjF which are precursors for BjF-4,5-dihydrodiol and BjF-9,10-dihydrodiol. Cyclodehydration of 2-[2-(9-methoxy-11-hydroxybenzo[a]fluoren-11-yl)ethyl]-1,3-dioxane in polyphosphoric acid afforded 4-methoxyBjF (from which the phenol is readily prepared) in 87% yield. Reaction of 1-(4-methoxyphenyl)-acenaphthylene with ethyl diazoacetate is catalyzed by copper-bronze and gave a mixture of diastereomeric cyclopropane carboxylates. These were converted to the corresponding aldehydes by diisobutylaluminum hydride reduction and Swern oxidation followed by cyclodehydration with polyphosphoric acid to give 10-methoxyBjF in 91% yield. It had previously been reported that reduction of BjF-4,5-quinone to BjF-4,5-dihydrodiol occurs in low yield due to overreduction to a mixture of tetrahydro diols and triols. We now report that complexation of the quinone with silver nitrate followed by reduction with potassium borohydride in the presence of oxygen affords BjF-4,5-dihydrodiol in 91% yield.<