Question

Write chemical equation for five methods of preparation of Ketones.

Hint:

Secondary alcohols $\rightarrow$ ketones by oxidation; alkenes $\rightarrow$ ketones by ozonolysis; benzene + acyl chloride $\rightarrow$ aryl ketone.

Answer 1

1. Oxidation of secondary alcohols:
\[ R{-}CH(OH){-}R' \xrightarrow{[O]} R{-}C(=O){-}R' + H_2O \]
2. Ozonolysis of alkenes:
\[ RCH{=}CHR' \xrightarrow[\ ]{O_3/Zn,H_2O} R{-}C(=O){-}R' \]
3. Friedel–Crafts acylation of aromatic compounds:
\[ C_6H_6 + RCOCl \xrightarrow{AlCl_3} C_6H_5COR + HCl \]
4. From calcium salts of carboxylic acids (dry distillation):
\[ (COO)_2Ca \;\xrightarrow{\Delta}\; R{-}C(=O){-}R + CaCO_3 \]
5. From nitriles (using dialkyl cadmium):
\[ RCN + R'_{2}Cd \;\longrightarrow\; R{-}C(=O){-}R' \]
Thus, ketones can be prepared by oxidation, ozonolysis, acylation, dry distillation, and nitrile methods.