2
$\begingroup$

Reaction scheme

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?

$\endgroup$
  • 6
    $\begingroup$ 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. $\endgroup$ – LDC3 Jul 26 '15 at 5:34
2
$\begingroup$

Initially, the oxygen in the ring gets protonated. However, there is no formation of a carbocation. The ring opening proceeds by an SN2 pathway, where iodide ion attacks at the less hindered carbon:

Mechanism of reaction

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.