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After this cyclic ether is activated with H+, will the bromide attack the more substituted site on the left or the less substituted side on the right? I think it will attack the right because SN2 favors less steric hindrance, but what is confusing me is that for acid activated epoxides, nucleotides attack the more substituted site. Can anyone clarify this for me? Does it have to do with the size of the ring? The charge of the nucleophile? Please help.

  • $\begingroup$ Which is the more stable cation after breaking of the C-O bond? $\endgroup$
    – Waylander
    Commented Jan 29, 2021 at 21:58
  • $\begingroup$ You will likely obtain 1,5-dibromohexane. The question is which intermediate bromo alcohol forms faster and by what mechanism.? $\endgroup$
    – user55119
    Commented Jan 29, 2021 at 21:58
  • $\begingroup$ related: chemistry.stackexchange.com/q/138998/102629 $\endgroup$
    – cngzz1
    Commented Jan 30, 2021 at 9:04
  • $\begingroup$ @cngzz1: The reaction you cited is not related here. This is ether opening. The reaction you mentioned is acetal opening. $\endgroup$ Commented Jan 30, 2021 at 16:15
  • 1
    $\begingroup$ @cngzz1: Yes, that could be related. $\endgroup$ Commented Jan 30, 2021 at 23:02


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