Eschenmoser fragmentation
The Eschenmoser fragmentation is a chemical reaction first published in 1967 by Swiss chemist Albert Eschenmoser. This reaction involves the interaction of α,β-epoxyketones with aryl sulfonylhydrazines to produce alkynes. Eschenmoser developed this reaction in collaboration with an industrial research group led by Günther Ohloff and applied it to the production of muscone and related macrocyclic musks[1].
The reaction mechanism of the Eschenmoser fragmentation begins with the condensation of an α,β-epoxyketone with an aryl sulfonylhydrazine. This hydrazone can either be protonated at the epoxide oxygen or deprotonated at the sulfonamide, and thus the fragmentation is catalyzed by acids or bases. Most common reaction conditions, however, are treatment with acetic acid in dichloromethane[1].
The Eschenmoser fragmentation has been used in various applications, including the synthesis of complex motifs and natural products[3]. It has also been used in the industrial scale production of certain compounds[1].
Citations:
[1] https://en.wikipedia.org/wiki/Eschenmoser_fragmentation
[2] https://www.sciencedirect.com/topics/chemistry/eschenmoser-tanabe-fragmentation
[3] https://pubmed.ncbi.nlm.nih.gov/24115282/
[4] https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Organic_Synthesis_(Shea)/03:_Neighboring_Group_Participation_Rearrangements_and_Fragmentations/3.04:_Fragmentations
[5] https://www.youtube.com/watch?v=OMfY68fMdcY
[6] https://link.springer.com/content/pdf/10.1007/978-3-319-03979-4_97.pdf
[7] https://onlinelibrary.wiley.com/doi/10.1002/anie.201209833
[8] https://www.youtube.com/watch?v=tFE3P3ILJIs
[9] https://diginole.lib.fsu.edu/islandora/object/fsu%3A291299/datastream/PDF/view
[10] https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/fragmentation-reaction
[11] https://synarchive.com/named-reactions/eschenmoser-fragmentation
[12] https://pubs.rsc.org/en/content/articlelanding/2013/ob/c3ob40800k
[13] https://en.wikipedia.org/wiki/Grob_fragmentation
[14] https://www.wikiwand.com/en/Eschenmoser_fragmentation
[15] https://chemistnotes.com/organic/eschenmoser-tanabe-fragmentationmechanism/
[16] https://www.chemeurope.com/en/encyclopedia/Eschenmoser_fragmentation.html
[17] https://www.sciencedirect.com/topics/chemistry/fragmentation-reaction
[18] https://onelook.com/?loc=olthes1&w=Eschenmoser+fragmentation