Domino allylic amination/Sonogashira/heterocyclisation reactions: palladium-catalysed three-component synthesis of pyrroles

International audienceThree-component reactions with 3,4-diiodoalk-2-enoic derivatives, primary amines, and terminal alkynes proceeded to give trisubstituted pyrroles in fair to good yields in the presence of palladium and copper catalysts under mild reaction conditions

Hemisynthesis and Absolute Configuration of novel 6-pentyl-2H-pyran- 2-one derivatives from Trichoderma spp

A comparative study of the secondary metabolism of two Trichoderma spp. with that of the Thctf1 transcription factor gene null mutant of Trichoderma harzianum 34 was carried out in order to deepen our knowledge of the biosynthetic pathway and mode of action of 6-pentyl-2H-pyran-2-one (1) and its derivatives as biocontrol agents. New isolated metabolites have shed light on the detoxification mechanism of 6-pentyl-pyranone by Trichoderma spp. All new compounds were synthesized and their stereoisomer characterized. The absolute configuration of 6-[(10R,20S)-dihydroxypentyl]-2H-pyran-2-one and 6-((10S,20R)-20-propyloxiran-1-yl)-2H-pyran-2-one was determined by NMR analysis of the corresponding Mosher’s esters

Dramatic influence of the substitution of alkylidene-5H-furan-2-ones in Diels-Alder cycloadditions with o-quinonedimethide as diene partner: en route to the CDEF polycyclic ring system of lactonamycin

International audienceAn efficient and rapid synthesis of the CDEF ring system of lactonamycinone is reported via a highly chemo- and diastereoselective intermolecular Diels-Alder cycloaddition between trans-1,2- disilyloxybenzocyclobutene and the appropriate γ-alkylidenebutenolide. The feasibility and the total chemoselectivity of the [4 + 2] cycloaddition for the construction of a spirolactone moiety via an intramolecular approach (IMDA) using both partners is also described demonstrating the versatility of the γ-alkylidenebutenolide building block