The order of reactivity of phenyl magnesium bromide (PhMgBr) with the following compounds: III > II > III > I > IIII > III > III > II > III

The order of reactivity of phenyl magnesium bromide (PhMgBr) with the following compounds is represented as I > II > III. As the number of alkyl groups increases or the size of the alkyl groups increases, the steric crowding increases and the ease of the nucleophilic attack of the grignard reagent on the carbonyl carbon decreases.