Chapter 3, Problem 49DSP

Interpretation Introduction

Interpretation:

The orientation of the $\text{OH}$ groups at C2 and C3 in the $\text{β-pyranose}$ form of D-ribose is to be identified.

Concept introduction:

The basic chair conformation of cyclohexane is shown below:

The substituents on alternate carbon atoms, which are on the same side of the ring, have the same orientation – either axial or equatorial.

Two substituents are cis to each other if they are on the same side of the ring.

Two substituents are trans to each other if they are on the opposite side of the ring.