Chapter 13, Problem 8MCP

Interpretation Introduction

Interpretation:

The structure $\text{β-D-fructose}$ has to be identified as acetal or hemiacetal and the explanation has to be given.

Concept Introduction:

Hemiacetal is characterized by a carbon, which is bonded to one hydroxyl group $\left(\text{-OH}\right)$ and one alkoxy group $\left(\text{-OR}\right)\text{.}$

Hemiacetals are unstable.  In the presence of acid and excess alcohol, they undergo a substitution reaction in which the $\text{-OH}$ group of the hemiacetal is exchange for another $\text{-OR}$ group from the alcohol.  The product formed is called as acetal.  A carbon bonded to two alkoxy groups $\left(\text{-OR}\right)$ is the called as acetal.