title: Dihydrothiophene
text: # Dihydrothiophene
  
  Dihydrothiophenes are heterocyclic organosulfur compounds. Two isomers are possible for the parent $C_4H_6S:$
  
  * 2,3-Dihydrothiophene, a vinyl thioether. CAS RN = 1120-59-8.
  * 2,5-Dihydrothiophene, an allylic thioether. A well-known derivative is 2,5-dihydrothiophene 1,1-dioxide. CAS RN = 1708-32-3.
  
  Depending on the substituents, some dihydrothiophenes are called 4,5-dihydrothiophenes.
  
  