Chapter 16.8, Problem 12P

Interpretation Introduction

Interpretation:

The products (in chair conformers formed), from the reaction of $\beta \text{-}$ D-galactose with ethanol and $\text{HCl}$ have to be drawn.

Concept Introduction:

Glycoside formation: carbohydrates react with an alcohol in acid which produce both anomers acetals are formed, if alkoxy group points down then it is α, alkoxy group points up then it is β.

Sugar molecule in which hydroxyl groups of first and sixth carbon atom are on the same side is known as $\alpha$ sugar, otherwise, $\beta$ sugar. Hydroxyl group of $\alpha$-sugar present on right side in Fischer projection is represented down in Haworth projection and at axial position in chair conformation.