Alkynes, also called acetylenes, are o hydrocarbons that contain a carbon carbon triple bond. acetylene itself, the simplest alkyne, was once widely used in industry as the starting material for the preparation of acetaldehyde, acetic acid, vinyl chloride, and other high- volume chemicals, but more efficient route using ethylene as starting material are now more commonOrganic Chemistry Organic Chemistry Xiamen Xiamen University University Alkynes, also called acetylenes, are hydrocarbons that contain a carbon￾carbon triple bond. Acetylene itself, the simplest alkyne, was once widely used in industry as the starting material for the preparation of acetaldehyde, acetic acid, vinyl chloride, and other high￾volume chemicals, but more efficient route using ethylene as starting material are now more common