Compounds containing a Six-membered Ring having two Hetero-atoms from Group VIB of the Periodic Table: Dioxanes, Oxathianes and Dithianes

This chapter discusses the dioxanes and related compounds, dithanes, dithiins and their benzo derivatives, oxathianes and oxathiins, and some miscellaneous compounds containing selenium or tellurium atoms. It also describes the general methods of preparation, properties, typical reactions and stereochemical aspects of this diverse group of compounds. Dioxanes and related compounds are covered under 1,2-Dioxanes, 1,2-dioxins , 1,3-Dioxanes , 1,4-Dioxanes , 1,4-dioxins groups. Structures equivalent to the dioxanes, in which both oxygen atoms are replaced by sulfur, are named dithanes, whereas structures analogous to the dioxins are known as dithiins. Analysis of dithanes, dithiins and their benzo derivatives includes the study of 1,2-Dithanes, 1,2-dithiins , 1,3-Dithianes, 2,4-dihydro-l,3-dithiins , 1,4-Dithiane, 1,4-dithiin and their benzo derivatives. Oxathianes and oxathiins contain one oxygen atom and one sulfur atom in a six-membered ring. They are thus mono thio analogues of the dioxanes and dioxiins, respectively and their study includes 1,2-Oxathianes and oxathiins, 1,3-Oxathianes, 1,4-Oxathianes, 2,4-dihydro-l,4-oxathiins and 1,4-oxathins, Benzoxathiins and their various derivatives. Miscellaneous compounds containing selenium or tellurium atoms, mentioned in this chapter are: 1,4-Oxaselenane (l,4-selenoxane), Phenoxaselenin, and Phenothiatellurin.