Related Experiment Video
Updated: Mar 13, 2026

1,3,5-Triphenylbenzene and Corannulene as Electron Receptors for Lithium Solvated Electron Solutions
Published on: October 10, 2016
Conformational Polymorphism of Lithium Pinacolone Enolate
Jie Guang1, Qiyong Liu1, Russell Hopson1
1Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States.
Abstract:
A metastable, polymorphic hexameric crystal structure of lithium pinacolone enolate (LiOPin) is reported along with three preparation methods. NMR-based structural characterization implies that the lithium pinacolate hexamer deaggregates to a tetramer in toluene but retains mainly the hexameric structure in nonaromatic hydrocarbon solvents such as cyclohexane. Moreover, the presence of a small amount of lithium aldolate (LiOA) dramatically influences the aggregation state of LiOPin by forming a mixed aggregate with a 3:1 ratio (LiOPin3·LiOA).
Related Concept Videos
α-Alkylation of Ketones via Enolate Ions
Reactivity of Enolate Ions
Regioselective Formation of Enolates
Stereochemical Effects of Enolization
Enolate Mechanism Conventions
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.

