The review is devoted to industrially important syntheses based on diacetylene, a side product from electrocracking, oxidative pyrolysis of methane and plasmochemical synthesis of acetylene. Reactions of diacetylene and its derivatives with mono- and dinucleophilic reagents occurring in the chemisorption of diacetylene from industrial gases and resulting in stable reactive compounds which can be used as valuable intermediates for organic synthesis and pharmaceutical industry are described. Some specific features of diacetylene reactions in superbasic media are discussed. The bibliography includes 266 references.