ISOLATION, STRUCTURAL ASSIGNMENT, AND SYNTHESIS OF N-(2-METHYL-3-OXODECANOYL)-2-PYRROLINE, A NEW NATURAL PRODUCT FROM PENICILLIUM-BREVICOMPACTUM WITH IN-VIVO ANTI-JUVENILE HORMONE-ACTIVITY

A new natural product with in vivo anti-juvenile hormone (JK) activity , N-(2-methyl-3-oxodecanoyl)-2-pyrroline (2), has been isolated from P enicillium brevicompactum Dierckx. Its structure has been tentatively assigned based on spectral data and unambiguously confirmed by alterna tive syntheses. Compound 2 has been prepared by means of a sequence of reactions beginning with acylation of Meldrum's acid by octanoyl chlo ride. The subsequent steps have been aminolysis of the resultant inter mediate with pyrrolidine,;alkylation of the active position with iodom ethane, introduction of a methoxy group in the pyrrolidine ring by ano dic oxidation, and final elimination of methanol through adsorption on SiO2 and heating. The natural product 2 and its bicyclic isomer ptyl- 3-methyl-4-oxo-6,7,8,8a-tetrahydro-4H-pyrrolo [2,1-b]-1,3-oxazine (3) are also obtained. This reveals that 2 can be biogenetically related t o the recently discovered brevioxime (1). Compound 2 and the synthetic precursors of 2 have shown important biological activities as insecti cides (against Oncopeltus fasciatus Dallas) and fungicides. The natura l product induces precocious metamorphosis in the target insect (70% p recocious adults at 10 mu g/nymph). In view of the above results, thes e products could be useful as lead molecules for the synthesis of anal ogues with enhanced biological activities.