Reduction of Aldehydes & Ketones to form Alcohol

$$\text{R--CHO} \xrightarrow{\text{NaBH}_4 \text{ or } \text{LiAlH}_4 \text{ or } \text{H}_2/\text{Ni}} \text{R--CH}_2\text{OH} \quad (1^\circ \text{ alcohol})$$

$$\text{R--CO--R'} \xrightarrow{\text{NaBH}_4 \text{ or } \text{LiAlH}_4 \text{ or } \text{H}_2/\text{Ni}} \text{R--CH(OH)--R'} \quad (2^\circ \text{ alcohol})$$