Question

When glycerol is treated with excess of $HI$, it produces:

• A. 2-iodopropane
• B. allyl iodide
• C. propene
• D. glycerol triiodide

Answer 1

Answer: (A)

2-iodopropane

When glycerol is treated with an excess of $HI$, it produces 2-iodopropane.

In the first step, a molecule of glycerol reacts with 3 $HI$ molecules to form unstable 1,2,3-triiodopropane. This loses a molecule of iodine to form allyl iodide.
Allyl iodide adds a molecule of $HI$ to obtain an unstable molecule which loses a molecule of iodine to form propene.

A molecule of $HI$ is added to propene to form 2-iodopropane.

Hence, the correct option is $\text{A}$