Evans aldol reaction
E635933
The Evans aldol reaction is a stereoselective carbon–carbon bond-forming reaction that uses chiral N-acyl oxazolidinone auxiliaries to control the configuration of aldol products.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Evans aldol reaction canonical | 2 |
How this entity was disambiguated
This entity first appeared as the object of triple T6994979 — 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: Evans aldol reaction Context triple: [David A. Evans, knownFor, Evans aldol 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.
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.
-
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.
Norrish 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.
-
E.
Eschenmoser sulfide contraction
Eschenmoser sulfide contraction is an organic rearrangement reaction that converts certain sulfur-containing intermediates into carbonyl compounds, widely used in complex molecule and natural product synthesis.
- 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: Evans aldol reaction Target entity description: The Evans aldol reaction is a stereoselective carbon–carbon bond-forming reaction that uses chiral N-acyl oxazolidinone auxiliaries to control the configuration of aldol products.
-
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.
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.
-
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.
Norrish 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.
-
E.
Eschenmoser sulfide contraction
Eschenmoser sulfide contraction is an organic rearrangement reaction that converts certain sulfur-containing intermediates into carbonyl compounds, widely used in complex molecule and natural product synthesis.
- F. None of above. chosen
Statements (50)
| Predicate | Object |
|---|---|
| instanceOf |
aldol reaction
ⓘ
carbon–carbon bond-forming reaction ⓘ organic reaction ⓘ stereoselective reaction ⓘ |
| allowsAccessTo |
anti aldol products
ⓘ
syn aldol products ⓘ |
| auxiliaryFeature |
covalently attached to substrate
ⓘ
induces high diastereoselectivity ⓘ recyclable ⓘ |
| auxiliaryRemovedBy |
hydrolysis
ⓘ
reductive cleavage ⓘ |
| controls |
relative configuration of aldol products
ⓘ
stereochemistry at the newly formed stereocenters ⓘ |
| developedInField | asymmetric induction ⓘ |
| givesProduct |
aldol adduct with defined stereochemistry
ⓘ
β-hydroxy carbonyl compound ⓘ |
| hasDiscoverer | David A. Evans ⓘ |
| hasKeyIntermediate |
chiral N-acyl oxazolidinone enolate
ⓘ
metal enolate ⓘ |
| hasMechanisticStep |
C–C bond formation
ⓘ
enolate formation ⓘ protonation of aldolate ⓘ |
| hasStereocontrolOrigin |
chiral auxiliary
ⓘ
oxazolidinone ring stereocenter ⓘ |
| hasStereoselectivityType |
diastereoselective
ⓘ
enantioselective (after auxiliary removal) ⓘ |
| isCategory | named reaction in organic chemistry ⓘ |
| isRelatedTo |
Evans auxiliary
ⓘ
chiral auxiliary methodology ⓘ |
| isUsedIn |
asymmetric synthesis
ⓘ
pharmaceutical synthesis ⓘ total synthesis of natural products ⓘ |
| namedAfter | David A. Evans ⓘ |
| stereochemicalOutcomeDependsOn |
enolate geometry
ⓘ
metal counterion ⓘ reaction conditions ⓘ |
| typicalAuxiliaryBackbone | oxazolidinone ⓘ |
| typicalAuxiliarySubstituent |
4-benzyl group
ⓘ
4-isopropyl group ⓘ |
| typicalElectrophile |
aldehyde
ⓘ
ketone ⓘ |
| typicalNucleophile | enolate of N-acyl oxazolidinone ⓘ |
| usesAuxiliary |
Evans chiral auxiliary
ⓘ
linked to:
Evans auxiliary-based asymmetric synthesis
|
| usesAuxiliary | chiral N-acyl oxazolidinone ⓘ |
| usesBase |
LDA
ⓘ
lithium diisopropylamide ⓘ strong non-nucleophilic base ⓘ |
| usesMetalCounterion |
boron
ⓘ
titanium ⓘ |
| usesMetalCounterion | lithium ⓘ |
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: Evans aldol reaction Description of subject: The Evans aldol reaction is a stereoselective carbon–carbon bond-forming reaction that uses chiral N-acyl oxazolidinone auxiliaries to control the configuration of aldol products.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.