# How can I predict the product of the reaction of 2-methyltetrahydrofuran with HI?

I am supposed to explain why treatment of 2-methyltetrahydrofuran with hydrogen iodide leads to the formation of 5-iodopentan-2-ol. However, I am getting stuck as it seems that the less stable primary carbocation is being preferentially formed, leading to the product. Is my mechanism incorrect?

• The reaction proceeds as either an $\ce {S_{N}1}$ or an $\ce {S_{N}2}$ mechanism. You need to review those mechanisms and determine which mechanism $\ce {I^-}$ would use.
– LDC3
Jul 26 '15 at 5:34