Norrish reaction
E557614
Norrish reaction subtype
intramolecular hydrogen abstraction reaction
organic chemistry reaction
photochemical cleavage reaction
photochemical reaction
The Norrish reaction is a photochemical process in organic chemistry involving the cleavage and rearrangement of carbonyl compounds under ultraviolet light, fundamental to understanding photodegradation and radical mechanisms.
All labels observed (2)
| Label | Occurrences |
|---|---|
| Norrish reaction canonical | 1 |
| Norrish type II reaction | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T5947775 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Norrish reaction Context triple: [Ronald George Wreyford Norrish, notableWork, Norrish reaction]
-
A.
Barton reaction
The Barton reaction is an organic photochemical transformation that converts nitrite esters into δ-nitroso alcohols via intramolecular hydrogen abstraction and radical rearrangement.
-
B.
Corey–Kim oxidation
Corey–Kim oxidation is an organic chemistry reaction that converts primary and secondary alcohols into aldehydes and ketones using N-chlorosuccinimide and dimethyl sulfide under mild conditions.
-
C.
Eschenmoser–Claisen rearrangement
The Eschenmoser–Claisen rearrangement is a variant of the Claisen rearrangement in organic chemistry that converts allylic alcohols and amides into γ,δ-unsaturated carbonyl compounds via a [3,3]-sigmatropic rearrangement.
-
D.
Eschenmoser–Tanabe fragmentation
The Eschenmoser–Tanabe fragmentation is an organic reaction that cleaves certain α,β-epoxy ketones or related substrates to form carbonyl compounds via a synthetically useful carbon–carbon bond fragmentation.
-
E.
Robinson annulation reaction
The Robinson annulation reaction is a classic organic chemistry transformation that forms six-membered rings by combining a Michael addition with an intramolecular aldol condensation, widely used in the synthesis of complex cyclic molecules and natural products.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Norrish reaction Target entity description: The Norrish reaction is a photochemical process in organic chemistry involving the cleavage and rearrangement of carbonyl compounds under ultraviolet light, fundamental to understanding photodegradation and radical mechanisms.
-
A.
Barton reaction
The Barton reaction is an organic photochemical transformation that converts nitrite esters into δ-nitroso alcohols via intramolecular hydrogen abstraction and radical rearrangement.
-
B.
Corey–Kim oxidation
Corey–Kim oxidation is an organic chemistry reaction that converts primary and secondary alcohols into aldehydes and ketones using N-chlorosuccinimide and dimethyl sulfide under mild conditions.
-
C.
Eschenmoser–Claisen rearrangement
The Eschenmoser–Claisen rearrangement is a variant of the Claisen rearrangement in organic chemistry that converts allylic alcohols and amides into γ,δ-unsaturated carbonyl compounds via a [3,3]-sigmatropic rearrangement.
-
D.
Eschenmoser–Tanabe fragmentation
The Eschenmoser–Tanabe fragmentation is an organic reaction that cleaves certain α,β-epoxy ketones or related substrates to form carbonyl compounds via a synthetically useful carbon–carbon bond fragmentation.
-
E.
Robinson annulation reaction
The Robinson annulation reaction is a classic organic chemistry transformation that forms six-membered rings by combining a Michael addition with an intramolecular aldol condensation, widely used in the synthesis of complex cyclic molecules and natural products.
- F. None of above. chosen
Statements (45)
| Predicate | Object |
|---|---|
| instanceOf |
Norrish reaction subtype
ⓘ
intramolecular hydrogen abstraction reaction ⓘ organic chemistry reaction ⓘ photochemical cleavage reaction ⓘ photochemical reaction ⓘ |
| alsoKnownAs | alpha-cleavage reaction ⓘ |
| canLeadTo |
chain scission in polymers
ⓘ
fragmentation of organic molecules ⓘ |
| category |
photodegradation process
ⓘ
radical reaction ⓘ |
| field |
organic chemistry
ⓘ
photochemistry ⓘ |
| hasHistoricalSignificance | contributed to development of modern photochemistry ⓘ |
| hasType |
Norrish type I reaction
ⓘ
Norrish type II reaction ⓘ |
| importantFor |
photostability analysis of organic materials
ⓘ
radical mechanism studies ⓘ understanding photodegradation of ketones ⓘ understanding photodegradation of polymers ⓘ |
| initiatedBy | ultraviolet irradiation ⓘ |
| involves |
1,4-biradical intermediate
ⓘ
C–C bond cleavage adjacent to carbonyl group ⓘ alpha-cleavage of carbonyl compounds ⓘ carbonyl compounds ⓘ excited triplet state ⓘ gamma-hydrogen abstraction ⓘ homolytic bond cleavage ⓘ intramolecular hydrogen transfer ⓘ radical intermediates ⓘ ultraviolet light ⓘ |
| mechanism |
excitation to singlet or triplet state followed by alpha-cleavage
ⓘ
photoexcitation followed by gamma-hydrogen abstraction and beta-scission or cyclization ⓘ |
| namedAfter | Ronald George Wreyford Norrish NERFINISHED ⓘ |
| occursIn |
solid phase
ⓘ
solution phase ⓘ |
| produces |
acyl radical
ⓘ
alkene ⓘ alkyl radical ⓘ cyclobutanol derivatives ⓘ enol ⓘ |
| relatedTo |
Paternò–Büchi reaction
NERFINISHED
ⓘ
photo-Fries rearrangement NERFINISHED ⓘ |
| requires |
carbonyl chromophore
ⓘ
light of appropriate wavelength ⓘ |
| studiedIn | physical organic chemistry ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Norrish reaction Description of subject: The Norrish reaction is a photochemical process in organic chemistry involving the cleavage and rearrangement of carbonyl compounds under ultraviolet light, fundamental to understanding photodegradation and radical mechanisms.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Norrish type II reaction