Synthesis and conformation of dithia[3]metacyclo[3]thiophenophanes and [2]metacyclo[2]thiophenophanes
摘要:
Dithia[3]metacyclo[3]- -(2,3)-, -(2,4)-, -(2,5)-, and -(3,4)thiophenophanes were prepared by dithiol bis-alkylations and were oxidized with m-chloroperbenzoic acid to the corresponding tetraoxides. Pyrolysis of the tetraoxides under a reduced pressure gave the corresponding [2]metacyclo[2]thiophenophanes together with many unexpected compounds. The conformations of the obtained products are also discussed.
Synthesis and conformation of dithia[3]metacyclo[3]thiophenophanes and [2]metacyclo[2]thiophenophanes
摘要:
Dithia[3]metacyclo[3]- -(2,3)-, -(2,4)-, -(2,5)-, and -(3,4)thiophenophanes were prepared by dithiol bis-alkylations and were oxidized with m-chloroperbenzoic acid to the corresponding tetraoxides. Pyrolysis of the tetraoxides under a reduced pressure gave the corresponding [2]metacyclo[2]thiophenophanes together with many unexpected compounds. The conformations of the obtained products are also discussed.
The synthesis of [2(4)](2,3,4,5)thiophenophane (superthiophenophane) (1), the first 'ultimate' heterophane, was accomplished in five steps from 3,4-bis(chloromethyl)-2,5-dimethylthiophene. In the respective C-13 NMR spectra, the signals due to the thiophene ring carbons of 1 appear at lower field than do those of the carbons of 2,10-dithia[3.2.2.3](2,3,4,5)thiophenophane (5). This shift is elucidated as a compression effect between facial p-orbitals of the thiophene carbons. The UV spectra of the two thiophenophanes are, however, almost identical. The results of X-ray crystallographic analysis show that 1 is a more strained molecule than 5.
Synthesis and conformation of dithia[3]metacyclo[3]thiophenophanes and [2]metacyclo[2]thiophenophanes
作者:Michinori Takeshita、Masashi Tashiro
DOI:10.1021/jo00008a046
日期:1991.4
Dithia[3]metacyclo[3]- -(2,3)-, -(2,4)-, -(2,5)-, and -(3,4)thiophenophanes were prepared by dithiol bis-alkylations and were oxidized with m-chloroperbenzoic acid to the corresponding tetraoxides. Pyrolysis of the tetraoxides under a reduced pressure gave the corresponding [2]metacyclo[2]thiophenophanes together with many unexpected compounds. The conformations of the obtained products are also discussed.