What is the major product of the following reaction?

Question

Quizplus · Accepted Answer

The reaction involves a substitution of the hydroxyl group of methanol with molecular iodine in the presence of red phosphorus. This is a standard example of the Williamson ether synthesis reaction. The product with the highest yield and likelihood is the one with a single substitution, which is III. The other products (I, II, IV, V) are less likely due to steric hindrance and/or unfavorable reaction conditions. Therefore, the major product of this reaction is III.

What Is the Major Product of the Following Reaction