Oxidation Reactions

$$1^\circ \text{ Alcohol} \xrightarrow{\text{PCC / PDC / Cu, 573K}} \text{R--CHO} \xrightarrow{\text{K}_2\text{Cr}_2\text{O}_7 / \text{H}^+} \text{R--COOH}$$

$$2^\circ \text{ Alcohol} \xrightarrow{\text{PCC / CrO}_3 / \text{Cu, 573K}} \text{Ketone}$$ (resistant to further mild oxidation).

$$3^\circ \text{ Alcohol} \xrightarrow{\text{Cu, 573K}} \text{Alkene}$$ (Undergoes dehydration instead of oxidation)