Describe different methods for the preparation of ketones with suitable chemical reactions.

(N/A) From Acyl Chlorides: Reaction of $RCOCl$ with dialkylcadmium $(R'_2Cd)$,prepared from Grignard reagent $(R'MgX)$ and $CdCl_2$,gives ketones: $2RCOCl + R'_2Cd \rightarrow 2RCOR' + CdCl_2$.
$(b)$ From Nitriles: Treatment of nitriles with Grignard reagent followed by hydrolysis yields ketones: $RCN + R'MgX$ $\rightarrow RR'C=NMgX$ $\xrightarrow{H_3O^+} RCOR' + NH_3 + Mg(OH)X$.
$(c)$ Friedel-Crafts Acylation: Benzene or substituted benzenes react with acid chlorides $(RCOCl)$ or acid anhydrides $(RCO)_2O$ in the presence of anhydrous $AlCl_3$ to form aromatic ketones: $C_6H_6 + RCOCl \xrightarrow{Anhydrous \ AlCl_3} C_6H_5COR + HCl$.