Lipase-Catalyzed Asymmetric Dealkoxylcarbonylation of σ-Symmetrical β-Ketodiesters and Its Application to the Synthesis of (-)-Podocarpic Acid

Abstract

Optically active 2,6-dimethylcyclohexanone-2-carb­oxylate was prepared by PLE-catalyzed dealkoxycarbonylation of σ-symmetrical β-ketodiesters, which possess quarternary carbons at α- and α′-positions. Moreover, (-)-podocarpic acid was prepared in a short sequence from 2,6-dimethylcyclohexanone-2-carboxylate.

dealkoxycarbonylation - PLE catalysis - β-ketodiesters - hydrolysis

References

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As shown below, the singlet signal assigned to the α-methyl group of 2a-cis appeared at lower magnetic field than that of 2a-trans, while methyl signals as doublets were observed at almost the same chemical shift.
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