Himic Anhydride: A Retro Diels-Alder Reaction for the Organic Laboratory and an Accompanying NMR Study
Lee T Birchall1, Sara Shehata1, Christopher J Serpell1
1Supramolecular Interfacial Synthetic Chemistry Group, School of Physical Sciences, Ingram Building, University of Kent, Canterbury CT2 7NH, United Kingdom.
Abstract:
The thermal equilibration of himic anhydride [IUPAC (2-endo,3-endo)-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid anhydride] to (2-exo,3-exo)-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid anhydride and subsequent recrystallization of the exo-product can be performed as a standard undergraduate laboratory experiment requiring minimal equipment. The interpretation of the 1H NMR spectra for these norbornene carboxylic anhydride molecules promotes an appreciation of constrained ring systems and factors that affect chemical shifts and coupling constants.
Related Concept Videos
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Diels–Alder Reaction: Characteristics of Dienes
Characteristics of the diene
Conformation
The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is...
Diels–Alder Reaction: Characteristics of Dienophiles
Characteristics of Dienophiles
Generally, the best dienophiles are alkenes containing electron-withdrawing substituents such as carbonyl, nitrile, and nitro groups. The feasibility of a Diels–Alder reaction depends...
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
¹H NMR of Labile Protons: Deuterium (²H) Substitution


