Lecture, three hours; discussion, one hour. Enforced requisite: course 30B with grade of C- or better. Third term of organic chemistry for Chemistry, Biochemistry, and engineering majors. Chemistry of enolates, enamines, dicarbonyl compounds, and amines. Molecular orbital theory and conjugated pi systems; UV/vis spectroscopy. Aromaticity and reactions of aromatic molecules. Heterocycles, pericyclic reactions, carbohydrates, and lipids. P/NP or letter grading.