Synthesis of a series of novel polycyclic aromatic systems: isomers of benz[a]anthracene containing a cyclopenta-fused ring

Abstract

The four possible isomers of benz [o]anthracene containing a cyclopenta-fused ring have been synthesized and characterized. These systems are of interest for structure-activity studies in bioactivation because of their predicted high level of activity. Formation of fused five-membered rings by intramolecular cyclodehydration, often difficult to accomplish, was found to be smoothly effected in anhydrous HF, provided the reactivity index (Nt) for the appropriate electrophilic addition was favorable. The dihydro polycyclic aromatic alcohols obtained from reduction of the corresponding keto cyclodehydration products were best dehydrated to the desired PAH by activity grade I neutral alumina in refluxing benzene. This dehydration proceeds in high yield without the formation of isomeric or polymeric side products that occurred even under such mild acid catalysis as p-toluenesulfonic acid.Recent confirmation of the mutagenicity and carcinogenicity of cyclopentatcdjpyrene1 (CPP, 1) and development of screening systems based on structure-activity

Examination of the nitromethane selective quenching rule in micellar anionic sodium dodecylbenzenesulfonate and micellar cationic dodecylethyldimethylammonium bromide solvent media

“…The double bond is alkenic in nature, rather than aromatic as one might believe and should not be included as part of the aromatic ring system when determining whether the compound is an alternant versus nonalternant PAH. This observation is confirmed by independent NMR coupling measurements [13][14][15][16]. Moreover, for cyclopent[fg]acenaphthylene, where movement of the double bonds in the two cyclopenta-rings leads presumably to a valid fourth resonance structure, Freiermuth et al [17] …”

Total synthesis of monosporascone and dihydromonosporascone

“…Approach 2: via a diarylketone (37) Our first venture in this area mirrored the approach outlined in Scheme 4. Addition of one equivalent of aryllithium 25 to diester 21 did give the desired ketone 37, but only in low yield and, not unexpectedly, accompanied by the corresponding tertiary alcohol arising from double addition (Scheme 6).…”

Polycyclic aromatic hydrocarbons and thiaarenes in the emission from hard‐coal combustion†

“…Besides cyclopenta(cd)pyrene, small amounts of three other ace compounds with suspected carcinogenicity 10 have been detected, namely acephenanthrylene, benz(e)-and benz(j)aceanthrylene. The occurrence of these compounds is noteworthy in view of their sensitivity towards oxygen.…”