O CH3 – CH2 – CH2 – C – OH HO – CH3 butanoic acid methanol CH3 – CH2 – CH2 – C – O O H H2O HO – CH3 methyl butanoate condensation occurs water eliminated

O H CH3 – CH2 – CH2 – C – OH H – N – CH3 butanoic acid methanamine CH3 – CH2 – CH2 – C – O H O H2O H H – N – CH3 N-methyl butanamide condensation occurs water eliminated

carboxylic acid group amine group – CH2 – CH2 – C – N – CH – N – C – CH2 – CH2 – C – O H CH3 – N – CH – N – C – CH2 – CH2 – C – N – CH – O H CH3 OH H H2O hydrolysis occurs (amide breaks)