Attempted Synthesis and Theoretical Calculations of the Elusive Polycyclic Arene Episulfides

Abstract

In pursuit of the thus far illusive polycyclic arene episulfides (PAE)as model compounds for further study in relation to chemistry-based cancer researchwe have attempted the synthesis of phenanthrene episulfide by using phenanthrene oxide, phenanthrene, and 5,7-dihydrodibenzo[c,e]thiepin as key starting materials. Following preliminaty theoretical calculations of the targeted PAE's, the synthesis of 9,10-episulfide-trans-7,8-dihydroxy-7,8-dihydro[a]pyre.ne has been initiated. Our results indicate that apparently the elusive phenanthrene episulfide has been formed through the use of selected sulfur transfer agents, but the conditions to avoid its desulfurization should be worked out.

Calculations Related to the Reactivity of Polycyclic Aromatic Hydrocarbon Episulfides

“…However, the thermodynamic [7] and kinetic [8] instability of the aromatic episulfides has complicated the synthesis of such compounds [9], and only a few have been isolated [10]. An attempted experimental work together with theoretical calculations oriented to direct the efforts for synthesizing polycyclic arene episulfides to make them available for cancer-related research has been reported lately [11a].…”

Reactive Site Model of the Reduction of SO2 on Graphite

“…Polycyclic arene episulfides (thiiranes) are highly unstable both thermodynamically 74 and kinetically, 75 and consequently, only few polycyclic aromatic episulfides have been synthezised so far. They undergo easy thermal desulfurization because the driving force toward aromatization, therefore, their thermodynamic stability increases the higher is the aromatic character of the ring system.…”

Quantum Chemical Studies on Ultimate Carcinogenic Metabolites from Polycyclic Aromatic Hydrocarbons

“…Polycyclic aromatic episulfides, the sulfur analogues of PAH epoxides, maintain the basic requirements of PAH carcinogenicity [41], although the thermodynamic [76] and kinetic [77] instability of the aromatic episulfides has complicated the synthesis of such compounds. However, the synthesis as well as studies on the cytotoxicity and mutagenicity of some aromatic diol episulfides have been recently accomplished [78][79][80].…”