CHEM 372 Lecture Notes - Lecture 17: Malonic Ester Synthesis, Diethyl Malonate, Enol
Document Summary
Chapter 23, 3rd edition: 1, 5-20, 21-28, 30, 32-34, 45-54, 58, 59, 64, 65. Chapter 23, 4th edition: 1, 2, 4-6, 10-13, 16-20, 21-28, 32-36, 38, 39, 44-48, 50-53, 58, 62. Warm-up problem: draw the products for the following reactions: Malonic ester synthesis: results in an alkylated carboxylic acid. Enolate alkylation (first set of steps: followed by hydrolysis and decarboxylation. Naoetbrooooh3o+oohheat123412233442. oooohoetna+oooobroooopka = 13sn2ooooh3o+oooohhco2oohhoohesterhydrolysis(seemechanism,3/17/09notes,p. 3)heatdecarboxylationketo-enoltautomerism since the malonic ester has two acidic protons, sometimes dialkylation can occur. The reaction can also form a cyclic alkane: Naoetbroooooohheat123412233442. br5br5oooonaoeth3o+512345acetoacetic ester synthesis: very similar reaction, results in a ketone. Overall reaction: enolate alkylation (first set of steps) note that there is more than one set of acidic protons. Why: alkylation is followed by hydrolysis and decarboxylation. Naoetbroooh3o+oheat2. ooohhoetna+ooobrooopka = 11, more acidic,so deprotonated atequilibriumpka = 19sn2oooh3o+ooohco2ohohydrolysisheatdecarboxylationo dialkylation can also occur for this reaction. Can a tertiary carbon be deprotonated in either the malonic ester synthesis or the acetoacetic ester synthesis: sure!