For the mechanism of CH3CH2OH + HBr giving CH3CH2Br + H2O.....can we write the mechanism of alcohol acting as an electrophile? I mean it's the same as SN2 right? The nucleophile attacks from the backside n all.??
Alcohol do not act as electrophile, it act as nucleophile.
Here, reaction of ethanol with HBr follows the SN2 mechanism.
In ethanol, OH is poor leaving group, so first it is protonated to make it a better leaving group. Then Br- attacks from back side.
Since the ethyl carbocation formed by the loss of water molecule is not stable, therefore it does not follow SN1mechanism.
So mechanism can be written as:
Here, reaction of ethanol with HBr follows the SN2 mechanism.
In ethanol, OH is poor leaving group, so first it is protonated to make it a better leaving group. Then Br- attacks from back side.
Since the ethyl carbocation formed by the loss of water molecule is not stable, therefore it does not follow SN1mechanism.
So mechanism can be written as: