There seems to be multiple forms of $\ce{HI}$ used to cleave epoxides:

conc. $\ce{HI}$, anhydrous $\ce{HI}$, cold $\ce{HI}$, hot $\ce{HI}$, cold conc. $\ce{HI}$, hot conc. $\ce{HI}$, etc.

So, does concentration of $\ce{HI}$ and temperature have any significance in determining the product?


for unsymmetrical epoxides or oxiranes reaction takes place in this way:

in acidic medium- ring on reaction with HI ring opens from more hindered side i.e., the more hindered C-O bond. So the carbon in which more number of groups are attached which is bonded to the oxygen in ring gets -I.

in basic medium- the ring opens from less hindered side.

temperature is not a much important factor in this reaction.

| improve this answer | |
  • 1
    $\begingroup$ Welcome to chemistry.se! While there is certainly some truth to what you have written, I think it would be better to beck it up with some references; especially the last sentence. I also think this does not address the question completely. $\endgroup$ – Martin - マーチン Mar 25 '19 at 15:20

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.