Optically active arene oxides, synthesis

In the aromatic-ring-annelated oxepin series the resonance effect is clearly the major influence dominating other factors (e.g. temperature, solvent, etc.) which affect the oxepin-arene oxide equilibrium. It is however very difficult to exclude the presence of a minor (spectroscopically undetectable) contribution from either tautomer at equilibrium. This problem has been investigated by the synthesis of chiral arene oxides from polycyclic aromatic hydrocarbons (PAHs). The presence of oxepin (26) in equilibrium with naphthalene 1,2-oxide has been excluded by the synthesis of the optically active arene oxide which showed no evidence of racemization in solution at ambient temperature via the achiral oxepin (26) <79JCS(Pl)2437>. 

Synthesis and Reactivities of Aromatic Oxides. Certain optically active arene oxides, which are of biological significance as metabolites of polycyclic aromatic hydrocarbons (PAH), undergo spontaneous racemisation. The most plausible mechanism for this involves ring opening to the corresponding oxepins... 

Asymmetric synthesis of Ar(CH2) S CHCl2.1 Oxidation (NaOCl) of arene-thioacetates, Ar(CH2)nSCH2COOR, complexed with p-cycloodextrin results in optically active a,oi-dichlorosulfoxides in 4-54% ee in 70-83% chemical yield. The highest optical yield is obtained in the oxidation of C6H5SCH2COOBu. 

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