Syntheses of stereochemically restricted lactone-type analogues of jasmonic acids

Enantioselective synthesis of both enantiomers of dimethyl cis-(4-acetoxycyclopent-2-enyl)malonate, key intermediates for epijasmonate

Both enantiomers (3 and 4) of dimethyl cis-(4-acetoxycyclopent-2-enyl)malonate (3), known intermediates for the synthesis of epijasmonate, were prepared in an enantio-enriched form from common starting material 2 based on desymmetrization of the meso-character by palladium-catalyzed asymmetric allylic alkylation.

Synthesis and potato cell expansion-inducing activity of the stereochemically restricted bicyclic analogue of 7-epi-jasmonic acid

The stereochemically restricted bicyclic analogue of 7-epi-jasmonic acid was synthesized from a known bicyclo[3.3.0]octane derivative. The enol triflate derived from the bicyclic compound was subjected to palladium-catalyzed coupling with allyltributyltin to give the desired carbon skeleton. Selective catalytic hydrogenation and subsequent acidic hydrolysis gave a new bicyclic analogue of 7-epi-jasmonic acid. The ACC conjugate of the bicyclic analogue was also synthesized. This ACC conjugate exhibited only slightly weaker potato cell expansion-inducing activity than that of the JA standard.