Nucleophilic Addition (General)

$\text{R}_2\text{C=O} + \text{Nu}^- \rightarrow \text{R}_2\text{C(Nu)(O}^-) \xrightarrow{\text{H}^+} \text{R}_2\text{C(Nu)(OH)}$

Aldol Condensation (Acetaldehyde — named reaction)

$2\text{CH}_3\text{CHO} \xrightarrow{\text{dil. NaOH}} \text{CH}_3\text{CH(OH)CH}_2\text{CHO} \xrightarrow{\Delta} \text{CH}_3\text{CH=CHCHO} + \text{H}_2\text{O}$

Step 1 (addition): beta-hydroxy aldehyde (3-hydroxybutanal, the "aldol") Step 2 (dehydration, heat): 2-butenal (crotonaldehyde, SMILES: C/C=C/C=O)

Cannizzaro Reaction

$2\text{RCHO} \xrightarrow{\text{conc. NaOH}} \text{RCOO}^-\text{Na}^+ + \text{RCH}_2\text{OH}$

(R = H for HCHO, C6H5 for benzaldehyde, (CH3)3C for pivaldehyde)

Haloform Reaction

$\text{CH}_3\text{COR} + 3\text{I}_2 + 3\text{NaOH} \rightarrow \underbrace{\text{CHI}_3}_{\text{yellow ppt}} + \text{RCOONa} + 3\text{NaI} + 2\text{H}_2\text{O}$

Reduction Equations

Grignard Addition Hierarchy

$\text{HCHO} + \text{RMgX} \rightarrow \text{R-CH}_2\text{OH} \text{ (1°)}$ $\text{RCHO} + \text{R'MgX} \rightarrow \text{RCH(OH)R'} \text{ (2°)}$ $\text{R}_2\text{CO} + \text{R'MgX} \rightarrow \text{R}_2\text{C(OH)R'} \text{ (3°)}$