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 oxidativecycloaddition of 3,4-dibromo-[n](2,5)thiophenophanes 12b–e and (2,4)[8]thiophenophane 16 with dienophiles gave stereoselectively OS-bridged cycloadducts 18, 19 and 24. The X-ray analysis of cycloadduct 18a shows it to have a rigid conformation. The molecules can be regarded as a new series of paddlanes. Under the same oxidative conditions, 3,4-dibromo-[8](2,5)thiophenophane (12a) gave