Definition

Alkyl halides treated with acetylide anions will undergo SN2 reactions to give alkynes.

Structural reaction scheme for Acetylide addition [RC≡C(–)], diagram 1 of 2
Figure 1. Acetylide addition [RC≡C(–)]

Explanation

Acetylide anions are the conjugate base of acetylenes (alkynes), and this is a commercial way to obtained alkynes. This process is only efficient with primary alkyl halides, possibly secondary which can undergo E2 mechanism because of steric hindrance of the leaving group.

Structural reaction scheme for Acetylide addition [RC≡C(–)], diagram 2 of 2
Figure 2. Acetylide addition [RC≡C(–)]