The Eschenmoser fragmentation, first published in 1967, is the chemical reaction of α,β-epoxyketones (1) with aryl sulfonylhydrazines (2) to give alkynes (3) and carbonyl compounds (4). This reaction is named after the Swiss chemist Albert Eschenmoser, who devised it in collaboration with an industrial research group around Günther Ohloff in Firmenich for the production of muscone and related macrocyclic musks. Hence, the reaction is also known as Eschenmoser–Ohloff fragmentation. In the same year, i.e. 1967, Masato Tanabe et al. of SRI International published an article detailing the reaction, and thus, some also refer to it as the Eschenmoser–Tanabe fragmentation.