Question

draw the major organic products of the following reactions.

Draw the major organic product(s) of the following reaction (multiple products may be drawn in one box): Draw the major organic product(s) of the following reaction (multiple products may be drawn in one box):

Answer 1

Concepts and reason

The problem is based on the concept of nucleophilic substitution reaction and carbocation rearrangement.

In nucleophilic substitution reaction, an electron rich species termed as nucleophile attacks the electrophilic center of an atom to replace a leaving group.

The preference of nucleophilic substitution of alcohol for a strong nucleophile such as ${\rm{B}}{{\rm{r}}^ - }$ follows ${\rm{S}}{{\rm{N}}_2}$

Fundamentals

Carbocations are stabilized by adjacent electron donating groups. Generally tertiary carbocation is more stable than secondary which is more stable than primary carbocation due to electron donating effect of alkyl group.

(a)

Hydroxy group of alcohol is easily protonated and ${\rm{B}}{{\rm{r}}^ - }$ act on primary alcohol through ${\rm{S}}{{\rm{N}}_2}$ mechanism, then ${{\rm{H}}_{\rm{2}}}{\rm{O}}$ behave as a good leaving group.

(b)

Oxygen has high affinity for hydrogen atom. Hence it gets protonated easily.

Ans: Part a

The major product is: