H1 Preparation of alkenes and alkynes Alkenes can be synthesized 1.by the reduction of alkynes,or 2.by the elimination of alkyl halides and alcohols. 3.Vicinal dibromides can be debrominated by treatment with zinc dust in acetic acid or with sodium iodide in acetone. Zn/HOAc or Nal,acetone Fig.1.Synthesis of an alkene from a vicinal dibromide. College H1 Preparation of alkenes of Science and alkynes „Alkenes can be synthesized 1.by the reduction of alkynes, or 2.by the elimination of alkyl halides and alcohols. 3.Vicinal dibromides can be debrominated by treatment with zinc dust in acetic acid or with sodium iodide in acetone