Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Photochemical Electrocyclic Reactions: Stereochemistry01:26

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Thermal Electrocyclic Reactions: Stereochemistry01:17

Thermal Electrocyclic Reactions: Stereochemistry

The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
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.
SN2 Reaction: Stereochemistry02:23

SN2 Reaction: Stereochemistry

In an SN2 reaction, the nucleophilic attack on the substrate and departure of the leaving group occurs simultaneously through a transition state. As the nucleophile approaches the substrate from the back-side, the configuration of the substrate carbon changes from tetrahedral to trigonal bipyramidal and then back to tetrahedral, leading to an inversion in the configuration of the product.
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not observed.
Stereoisomers02:32

Stereoisomers

On the basis of mirror symmetry, stereoisomers of an organic molecule can be further classified into diastereomers and enantiomers. Diastereomers are stereoisomers that are not mirror images of each other. Substituted alkenes, such as the cis and trans isomers of 2-butene, are diastereomers, as these molecules exhibit different spatial orientations of their constituent atoms, are not mirror images of each other, and do not interconvert. Here, the interconversion is suppressed due to restricted...
SN1 Reaction: Stereochemistry02:15

SN1 Reaction: Stereochemistry

This lesson provides an in-depth discussion of the stereochemical outcomes in an SN1 reaction.
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
¹H NMR: Long-Range Coupling01:27

¹H NMR: Long-Range Coupling

The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Accessing Medium-Sized Bridged Heterocycles via EnT-Catalyzed Intermolecular Dearomative (5 + 4) Cycloaddition of Furans and Oxazoles.

Journal of the American Chemical Society·2026
Same author

Cholesterol and Cholesterol-Derived Molecules Differentially Modulate Neuronal Kv7.2/7.3 Channels.

Archiv der Pharmazie·2026
Same author

Step-Edge Functionalization by N-Heterocyclic Carbenes Enhances Catalytic Activity in Electrochemical CO<sub>2</sub> Reduction.

Advanced materials (Deerfield Beach, Fla.)·2026
Same author

Energy-Transfer Catalysis Enables the Birch-Type Reduction of 2-Pyridones.

Angewandte Chemie (International ed. in English)·2026
Same author

A Cholesterol Analogue for Cell-Surface Enzyme Display.

Angewandte Chemie (International ed. in English)·2026
Same author

Diastereoselective synthesis of 1,4,8-trisubstituted perhydroquinolines as novel κ receptor agonists.

Organic & biomolecular chemistry·2026
Same journal

A rechargeable non-aqueous Mg-O<sub>2</sub> battery based on magnesium peroxide chemistry.

Nature chemistry·2026
Same journal

Setting a direction for molecular motors.

Nature chemistry·2026
Same journal

Driving movement in the field of molecular machines.

Nature chemistry·2026
Same journal

First ladies of chemistry.

Nature chemistry·2026
Same journal

How isoprene connects plants to global climate.

Nature chemistry·2026
Same journal

One-dimensional carbon chains free of end-capping groups.

Nature chemistry·2026
See all related articles

Related Experiment Video

Updated: Jun 6, 2026

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
08:51

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

Published on: August 18, 2017

Cross-coupling: stereochemistry by remote control

Frank Glorius

    Nature Chemistry
    |December 3, 2010
    PubMed
    Summary

    No abstract available in PubMed .

    More Related Videos

    Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols
    10:12

    Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols

    Published on: April 4, 2014

    Isolation of Labile Multi-protein Complexes by in vivo Controlled Cellular Cross-Linking and Immuno-magnetic Affinity Chromatography
    10:50

    Isolation of Labile Multi-protein Complexes by in vivo Controlled Cellular Cross-Linking and Immuno-magnetic Affinity Chromatography

    Published on: March 9, 2010

    Related Experiment Videos

    Last Updated: Jun 6, 2026

    Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
    08:51

    Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

    Published on: August 18, 2017

    Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols
    10:12

    Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols

    Published on: April 4, 2014

    Isolation of Labile Multi-protein Complexes by in vivo Controlled Cellular Cross-Linking and Immuno-magnetic Affinity Chromatography
    10:50

    Isolation of Labile Multi-protein Complexes by in vivo Controlled Cellular Cross-Linking and Immuno-magnetic Affinity Chromatography

    Published on: March 9, 2010