Chapter 18, Problem 18.88P

Interpretation Introduction

Interpretation:

When $\text{1},\text{5}-\text{diketone}$ is treated with acid, a $\text{2},\text{6}-\text{dialkyl pyran}$ is produced. The mechanism for this reaction is to be proposed.

Concept introduction:

Both source molecule $\text{1},\text{5}-\text{diketone}$ and target molecule $\text{2},\text{6}-\text{dialkyl pyran}$ have the same number of carbon atoms, which shows that no outside source of carbon is needed. Only difference is that the source has two oxygen atoms whereas the target molecule has only one oxygen with cyclic compound. Therefore, E1 reactions and nucleophilic addition steps are followed to obtain the target molecule as the product.