Sulfur-containing five- and six-membered

Table I. Sulfur-Containing Five- and Six-Membered Ring Heterocyclic Compounds...

Sulfur containing heterocycles are also common Compounds m which sulfur is the heteroatom m three four five and six membered rings as well as larger rings are all well known Two interesting heterocyclic compounds that contain sulfur-sulfur bonds are hpoic acid and lenthiomne... 

Thus, the reaction of 4-dialkylaminobut-3-yn-2-ones with various bifunctional reagents makes it possible to carry out a targeted synthesis of five- and six-membered nitrogen-, oxygen-, and sulfur-containing heterocycles having two heteroatoms. 

Electrophilic cyclizations are useful for closure of a variety of oxygen-, nitrogen-, and sulfur-containing rings. The product structure depends on the ring size and the exo-endo selectivity. The most common cases are formation of five- and six-membered... 

Romers, C., Geometry and Conformational Properties of Some Five- and Six-Membered Heterocyclic Compounds Containing Oxygen and Sulfur, 4, 39. 

This reaction can be carried out internally, by treatment of sulfide ions with 1,4- or 1,5-dihalides, to prepare five- and six-membered sulfur-containing heterocyclic rings. 

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