Synthesis of natural compounds


Diverse natural and biologically active compounds, as well as analogues, have been obtained by our methodologies.


For example, the formal enantioselective synthesis of a natural compound such as roseophilin has been realized by exploiting the highly stereocontrolled cyclization of dienones in which one of the double bonds is embedded in a N-heterocyclic ring. More recently we have completed the synthesis of the Streptomyces alkaloid 4-epi-SS20846A as well as that of a natural alkaloid isolated from the Chines mangrove Sonneratia hainanensis and one alkaloid from Sedum sp. plants. By the tandem gold(I)-catalyzed [3,3]-rearrangement/Nazarov reaction strategy we have also carried out the first synthesis of bruceolline H and bruceolline I.




By exploiting the Nazarov reaction we also obtain novel and potent strigolactone analogues, which are compounds able to stimulate the AM fungi’s hyphal growth and parasitic plants’ seed germination. Strigolactone-analogues are also internal hormone which regulate the lateral growth of the plant. Several applications in agricolture can be envisaged and for this reason we are now developing synthetic methods for large scale synthesis as well as fluorescent derivatives for biochemical investigations.




Other natural compounds we have prepared include  the useful proline-mimetic 4-hydroxypipecolic acid, which has been obtained after methoxycarbonylation of a 4-hydroxy-substituted δ-valerolactam-derived enol phosphate whose enantioselective synthesis has been for the first time realized in our lab and which was also exploited for the synthesis of conformationally constrained derivatives. By the same approach we have also prepared both enantiomers of 3-hydroxypipecolic acid and 5-hydroxypipecolic acid as well as a series of 4,5-dihydroxypipecolic acids, which are rarer in nature and of which only a few syntheses have been reported so far.


Similarly, fagomine, deoxymannojirimycin, and dideoxymannojirimycyin, which are natural alkaloids and inhibitors of glycosidases, have been obtained by exploiting the chemistry of lactam-derived enol phosphates. These phosphates will certainly prove very useful for the synthesis of several natural compound containing a polyhydroxypiperidine nucleus and our efforts are now directed towards this end.