In these reactions if two reagent is given how to decide who is going to react with the compound.HBr is a strong acid CH3OH is a weak base.So HBr dissociate easily but CH3OH is reacting with the given compound. How is this possible??
$\begingroup$
$\endgroup$
Add a comment
|
2 Answers
$\begingroup$
$\endgroup$
0
Who said in the reaction ch3oh has to behave as an acid. It is acting as a nucleophile . It donates oxygen's lone pair to the vacant orbital of the carbonation intermediate forming an oxonium cation which then looses a molecule of H+ to form the product
PS: to form the carbonation intermediate the H+ was given by HBr which was given back during the last step of the rxn
$\begingroup$
$\endgroup$
0
No doubt that, HBr is strong and it would disassociate into $\text{H}^{+}$ and $\text{Br}^{-}$ but methanol is a solvent in the second reaction and it would attack the Carbocation because of higher concentration and it's a better nucleophile (-ve charge density on Oxygen atom is high) and then the Hydrogen atom would deprotonate.
One more question, why in the first reaction options, $\text{Br}$ is missing, as $\text{HBr}/\text{H}_{2}\text{O}$ is $\text{HOBr}$ in reaction.
