Summary of Synthesis of Alkenes
Dehydrohalogenation by E2 mechanism: Saytzeff and Hofmann products are possible depending on the base used.
Dehydrohalogenation by E1 mechanism: both substitution and elimination products are formed.
Dehalogenation of vicinal dibromides: occurs with the treatment of vic-dibromide with I- or Zn in acetic acid via an E2 mechanism.
Dehydration: involves conversion of the poor -OH leaving group into the good leaving group H2O.