(1 Z ,3 Z )-Buta-1,3-dienyl-1-lithium species and substituted tellurophenes by Te/Li exchange on (1 Z ,3 Z )-butyltelluro-1,3-butadienes and (1 Z ,3 Z )-1,4-bis(butyltelluro)-1,3-butadienes
(1 Z ,3 Z )-Buta-1,3-dienyl-1-lithium species and substituted tellurophenes by Te/Li exchange on (1 Z ,3 Z )-butyltelluro-1,3-butadienes and (1 Z ,3 Z )-1,4-bis(butyltelluro)-1,3-butadienes