4.3.1.3 Robinson-Schopf Reaction

Compounds that are enolic or potentially enolic react with a mixture of aldehydes and primary or secondary amine in the presence of an acid to afford amine salt which, after basification, gives an aminomethyl derivative. The reaction has found wide applications in organic synthesis. For example, the synthesis of tropinone can be accomplished in 90% yield. This reaction follows biomimetic approach to forming alkaloids.

Mechanism

The synthesis involves two Mannich reactions followed by spontaneous decarboxylation of the dibasic β-keto acid.