Freund reaction

Written by J.A Dobado | Last Updated on May 2, 2024

What is Freund reaction?

The Freund reaction is a process used to create alicyclic hydrocarbons by treating open chain dihalo compounds with sodium. When zinc is used instead of sodium, the reaction is known as the Gustavson reaction.

In addition, the Hass cyclopropane process involves the cyclization of 1,3-dichloropropane obtained from the chlorination of propane derived from natural gas. This is achieved by treating the compound with zinc dust in aqueous alcohol in the presence of catalytic sodium iodide.

Freund reaction
Freund reaction


  • A. Freund, “Über Trimethylen” [On trimethylene] Monatsh. Chem., 1882, 3, 625-635
    DOI: 10.1007/BF01516828
  • Gustavson, G. (1887), Ueber eine neue Darstellungsmethode des Trimethylens. [On a new method for the preparation of trimethylene] J. Prakt. Chem., 36: 300-303.
  • Synthesis of Cyclopropane
    H. B. Hass, E. T. McBee, and G. E. Hinds
    Industrial & Engineering Chemistry 1936 28 (10), 1178-1181
    DOI: 10.1021/ie50322a013