A straightforward synthesis of (E)-δ-alkenyl-β,γ-unsaturated δ-lactones by a tandem ring-closing/cross-coupling metathesis process
Résumé
The access to (E)-δ-alkenyl-β,γ-unsaturated δ-lactones starting from 3-O-(1,4-pentadienyl) 3-butenoate has been investigated by using a tandem process including two different metathesis reactions. By this way, new structures, isomers of natural compounds like argentilactone, were isolated in good yields. Reconjugation of the internal CC bond can be achieved under basic conditions to give α-pyrones.