Chapter 12, Problem 12.32P

Interpretation Introduction

Interpretation:

The mechanism for given reaction is to be drawn.

Concept introduction:

Heat or light causes a weak ${\text{C-N}}_{\text{2}}$ bond to break. In Step 1, the ${\text{C-N}}_{\text{2}}$ bond breaks when energy is absorbed from light and carbene is produced. Carbene species have a lone pair on electrophilic carbon. In Step 2, carbene reacts with $\text{C}\equiv \text{C}$ to generate the three-membered ring.