TOTAL SYNTHESIS OF SCELETIUM (AIZOACEAE) ALKALOIDS. THE CINNAMONITRILE ROUTE. THE TOTAL SYNTHESIS OF RACEMIC O-METHYL JOUBERTIAMINE AND MESEMBRINE

Abstract
A new method of synthesis of Sceletium (Aizoaceae) alkaloids based on the introduction of a “formyl anion” equivalent at the β-position of a cinnamonitrile, followed by Robinson annulation and final modification of the resulting cyanomethyl side chain is described. The method has been successfully applied to the total synthesis of racemic O-methyljoubertiamine (1) and mesembrine (2).