Dioxolane and 1,3-Dithiolane Derivatives

There are three isomeric parent systems 213, 214, and 215. Compounds belonging to 213 seem not to be described. 

From the basidiomycete Phlebia strigosozonata, a red pigment was isolated, phlebiarubrone, for which evidence as a 4,7-diphenyl derivative of 214 has been forwarded (63TL335 67T3985). Other derivatives of this system were prepared from the corresponding dimethoxy precursors with dilute nitric acid (72CB614). 

Representatives of the 215 system were obtained from phenolic precursors and Fremy s salt or CAN (79ZN(B)624 83ZN(B)392). They undergo a 

Diels-Alder reaction to give benzo analogs of 215 (83ZN(B)392), which were also obtained by bromine oxidation of the polycyclic precursors (86CZ455). Quinone 216 was prepared with diazomethane (83ZN(B)392). 

Quinones with a sulfur-containing annelated ring are strong electron acceptors and some of their charge transfer complexes with electron donors show high electrical conductivity (86CC1489). 

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