Question

Please let me know what would be the product when 2-ethyl-2,3-dimethyloxirane reacts with HBr ??????

Answer 1

2-Bromo-3-methylpentan-3-ol
or
2-Bromo-3-methyl-3-pentanol

Explanation:

I would suggest the following mechanism:

Step 1: Oxygen of the epoxy group will attack the hydrogen of the HBr and will form `Br^-` and the intermediate which has a good leaving group `R_2OH^+`.

Step 2: `Br^-` which is a nucleophile will attack the `2^(nd)` degree carbon in an `SN_2` mechanism to give the final product.