Question

Draw (a) a curved arrow mechanism of and (b) the side products that would result from reaction of (i) phenylmagnesium bromide and water and (ii) phenylmagnesium bromide and acetone.

Answer 1

1) Reaction & Mechanism of phenylmagnesium bromide with water is given in image.

Some important things about reaction and mechanism :-

• phenylmagnesium bromide react with water and give rise to benzene, with side product magnesiumhydroxy bromide.

• In mechanism, nucleophilic carbon of phenylmagnesium bromide attack on electrophilic proton of water and the formation of main product benzene and side product magnesiumhydroxy bromide take place.

2) Reaction & mechanism between phenylmagnesium bromide with acetone is given in image.

some important things about reaction & mechanism:-

• Phenylmagnesium bromide react with acetone and give rise to alcohol and side product magnesiumhydroxy bromide.

• In mechanism, nucleophilic carbon of phenyl magnesium bromide react with electrophilic carbon of carbonyl group of acetone and the double bond of carbon breaks into single bond & formation of tetrahedral intermediate take place.

• Finally this tetrahedral intermediate undergo hydrolysis and give rise to main product alcohol and side product magnesium hydroxy bromide.