Malonic Ester Synthesis: The 4-Step Route to Substituted Acetic Acids

Master malonic ester synthesis: deprotonation, SN2 alkylation, hydrolysis, and decarboxylation. Learn which alkyl halides work, how to avoid E2, and practice exam problems.

• Key nucleophile: Malonate enolate (stabilized by two esters)
• Key electrophile: Primary alkyl halide (SN2)
• Sequence: 1) Base → enolate 2) Alkylation 3) Hydrolysis 4) Decarboxylation
• Big trap: Tertiary/secondary electrophiles give E2 or fail
• Exam type: Synthesis / retrosynthesis
• Exam type: Predict the major product
• Exam type: Failure modes / distractors