Norrish-Yang reaction

{
  "id": "MLC-T-CHM-008082",
  "term": "Norrish-Yang reaction",
  "field": "Chemistry",
  "definition": "The photochemical formation of cyclobutanols from carbonyl compounds that bear a gamma hydrogen: the excited carbonyl abstracts that hydrogen through a six-membered transition state to give a 1,4-biradical, whose two radical centers then combine to close a four-membered ring. This ring closure competes with cleavage of the biradical to an alkene and an enol, which is the Norrish Type II fragmentation.",
  "subject": "Organic and Biomolecular Chemistry",
  "see_also": [
    "Norrish Type II photoreaction",
    "abstraction",
    "carbonyl compounds",
    "intramolecular"
  ],
  "references": [
    "PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 375 (https://doi.org/10.1351/pac200779030293)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/norrish-yang-reaction/"
}