Tropinone

tropinone is an alkaloid, synthesised in 1917 by Robert Robinson as a synthetic precursor to atropine, a scarce commodity during World War I.

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In organic chemistry the synthesis is considered a milestone in total synthesis. Tropinone is a complex bicyclic molecule but the reactants are fairly simple: succindialdehyde (see succinic acid and aldehydes), methyl amine and actone dicarboxylate (or even acetone). The synthesis is a good example of a biomimetic reaction or biogenetic-type synthesis because biosynthesis makes use of the same building blocks. It also demonstrates a tandem reaction is a one-pot synthesis.

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The main features apparent from the reaction sequence below are:

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• step 1: Nucleophilic addition of secondary amine to aldehyde followed by loss of water to create an imine
• step 2: nucleophilic addition of the imine to the second aldehyde unit and first ring closure
• step 3: intermolecular mannich reaction of the enolate of actone dicarboxylate
• step 4: new enolate formation and new imine formation with loss of water for
• step 5: second intramolecular mannich reaction and second ring closure
• step 6: loss of 2 carboxylic groups to tropinone
Tropinone: references ►



 

Alkaloid: An alkaloid is a nitrogenous organic molecule that has a pharmacological effect on humans and animals. The name derives from the word alkaline; originally, the term was used to describe any nitrogen-containing base (an amine in modern terms). Alkaloids are found as secondary metabolites in plants (e...

Robert Robinson: Famous people named Robert Robinson include:...

Synthetic: Generally, synthetic means pertaining to synthesis, i.e., the putting-together of two or more parts into a coherent whole, whether by design or by natural processes....