Chapter 11, Problem 58DSP

Interpretation Introduction

Interpretation:

The product of the reaction when the given nitrone undergoes intramolecular $\text{1,3-dipolar}$

cycloaddition is to be determined.

Concept introduction:

$\text{1,3-dipoles}$ are represented by a Lewis structure such that four electrons are delocalized over three atoms.

One of them is positively charged while the other is negatively charged.

This dipole acts as a $\text{4π}$ electron component and can add to a $\text{2π}$

electron component via the $\text{[4+2]-cycloaddition}$.

The $\text{2π}$

electron component can also be an alkyne which changes to an alkene upon addition.

The resultant structure contains a new five membered ring consisting of the $\text{1,3-dipole}$

attached to the two atoms of the alkyne.

The double bond between the carbon atoms of the alkene changes to a single bond.