A Novel Route to Iridoids: Enantioselective Syntheses of Isoiridomyrmecin and α-Skytanthine

Abstract

Enantio- and diastereoselective syntheses of the iridoids (-)-isoiridomyrmecin and (+)-α-skytanthine from a common intermediate (6-bromo-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]furan-2-one) were achieved. Key steps in both syntheses are conjugated nucleophilic substitutions (S_N2′ anti-reactions) with C₁ zinc cyanocuprates.

Key words

enantioselective synthesis - cuprates - natural products - zinc - alkaloids

References

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1

Ernst, M.; Helmchen, G. submitted.

9

This sequence of reactions was carried out with racemic compounds.

13

According to control experiments, phthalimide was formed during the preparation of the organozinc compound.