Question

What is the correct order of reactivity of alcohols in the following reaction?

$R-OH+HCl\stackrel{{ZnCl}_2}{\to }R-Cl+H_{2}O$

• A. 1${}^0$ > 2${}^0$ > 3${}^0$
• B. 1${}^0$ < 2${}^0$ > 3${}^0$
• C. 3${}^0$ > 2${}^0$ > 1${}^0$
• D. 3${}^0$ > 1${}^0$ > 2${}^0$

Answer 1

Answer: (C)

3${}^0$ > 2${}^0$ > 1${}^0$

The correct order of reactivity of alcohols in the following reaction is $3^0>2^0>1^0$

$R-OH+HCl\stackrel{{ZnCl}_2}{\to }R-Cl+H_{2}O$

In this substitution reaction, hydroxide ion is replaced by chloride ion.

It is used to classify the low molecular weight alcohols into primary secondary and tert alcohols.

The reagent is known as Lucas reagent.