Chugaev elimination

The Chugaev elimination is a chemical reaction that involves the elimination of water from primary alcohols to produce terminal alkenes. The intermediate is a xanthate. It is named for the Russian chemist Lev Aleksandrovich Chugaev (a.k.a. Leo Aleksandrovich Tschugaeff), born 16 October [O.S. 4 October] 1873, Moscow, died 9 October [O.S. 26 September] 1922.

Additional recommended knowledge

Daily Visual Balance Check

Correct Test Weight Handling Guide: 12 Practical Tips

Essential Laboratory Skills Guide

In the first step, a potassium xanthate is formed out of the alkoxide and carbon disulfide (CS₂). With iodomethane, it is transformed into a thioester.

At about 200 °C, the alkene is formed by a syn-elimination. In a 6-membered cyclic transition state the hydrogen atom is moved from the β-C-atom to the sulfur. The side product decomposes to carbonyl sulfide (OCS) and methanethiol.

References

Latscha, Hans P. Chemie-Basiswissen. Berlin(2002): Springer.