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Unformatted text preview: The Acetoacetic Ester Synthesis of Substituted Acetones A synthetic sequence starting from ethyl acetoacetate is a standard way to prepare methyl ketones (substituted acetones). It is called the acetoacetic ester synthesis . Synthetic Overview CH 3 C-C-CO 2 H O = R H hydrolysis CH 3 C-C-CO 2 C 2 H 5 O = H H CH 3 C-C-CO 2 C 2 H 5 O = R H alkylation CH 3 C-C-H O = R H decarboxylation alkylated methyl ketone alkylation CH 3 C-C-CO 2 C 2 H 5 O = R R' hydrolysis CH 3 C-C-CO 2 H O = R R' decarboxylation CH 3 C-C-H O = R R' dialkylated methyl ketone The ethyl acetoacetate serves as the synthetic equivalent of CH 3 C-C-H O = A More Detailed General Synthetic Scheme CH 3 C-CH 2-CO 2 C 2 H 5 O = pK a = 10.7 + NaOEt CH 3 C-CH-CO 2 C 2 H 5 O = :- Na + + EtOH (one full equivalent) RX alkylation CH 3 C-CH-CO 2 C 2 H 5 O = R + NaX dilute NaOH/H 2 O hydrolysis CH 3 C-CH-CO 2- Na + O = R H 3 O + acIDIfIcatIOn CH 3 C-CH-CO 2 H O = R 100 o C decarboxylation CH 3 C-CH 2 R O = + CO 2 Decarboxylation of the...
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This note was uploaded on 10/20/2009 for the course CHEM 322BL at USC.
- Organic chemistry