Chapter 20, Problem 20.41QP

Interpretation Introduction

Interpretation: Among the given structures, the $\text{β}$ isomers are to be identified.

Concept introduction: Cyclisation in the structure of monosaccharide occurs when the carbon backbone of the linear form curls around so that the $-\text{OH}$ group bonded to the carbon atom labeled number $5$ comes close to the aldehyde group on $\text{C}-1$. The aldehydes and alcohol groups react to form a six-membered ring made up of five carbon atoms and the oxygen atom of $\text{C}-5$ alcohol. There is a significant difference in the two cyclic structures.

To determine: The $\text{β}$ isomers among the given structures.