Synthesis of 2,5-dihydrotellurophene - A new heterocyclic compound

Article abstract of DOI:10.1021/ja00400a038

2,5-Dihydrotellurophene 1,1-dichloride was isolated in 62% yield when TeCl₄ was heated in acetonitrile with an excess of butadiene. Isoprene and 2,3-dimethylbutadiene reacted similarly affording the 3-methyl- and the 3,4-dimethyl-substituted 2,5-dihydrotellurophene 1,1-dichlorides which were easily reduced with aqueous Na₂S to the corresponding 2,5-dihydrotellurophenes. 2,5-Dihydrotellurophene could be converted to its 1,1-dibromide and 1,1-diiodide, respectively, by treatment with Br₂ and I₂. Treatment with XeF₂ afforded the 1,1-difluoride and oxidation with H₂O₂ similarly afforded 2,5-dihydrotellurophene 1-oxide, which was not isolated. The double bond of 2,5-dihydrotellurophene 1,1-dichloride was inert to treatment with Br₂ or Cl2, probably due to an interaction, either steric or electronic, with the TeCl₂ group.