Which is the major product of the following reaction?

Question

Quizplus · Accepted Answer

The reaction involves the reaction of a primary alcohol with HBr in the presence of PBr3. This is a typical SN2 reaction in which the nucleophile (Br-) attacks the carbon that is attached to the leaving group (-OH). The product will be an alkyl bromide, which is expected to have the same carbon skeleton as the starting material. Therefore, the only possible product is III. The other options (I, II, and IV) are not possible because they have a different carbon skeleton from the starting material.

Which Is the Major Product of the Following Reaction