Alkynes

Alkynes are compounds that possess carbon-carbon triple bonds.

The reactions of alkynes are similar to those of alkenes. In an electrophilic addition, the electronegative group will attach to the more substituted carbon (Markownikoff's rules for alkenes). However, since we are making an alkene, we need to be concerned with the relative stereochemistry (cis and trans) of the addition process. Due to steric considerations, trans addition is almost exclusively favored in all electrophilic additions to alkynes.