LIGNANES.10. PREPARATION DES (R)-(+) ET (S)-(-)-β-PIPERONYL ET β-VERATRYL-γ-BUTYROLACTONES ET LEUR UTILISATION DANS LA SYNTHESE TOTALE DE LIGNANES OPTIQUEMENT ACTIFS

Article abstract of DOI:10.1016/0040-4020(89)80041-9

A simple and efficient route leading to optically active β-benzyl-γ-butyrolactones is described.Thus, the methyl (R,S)-α-benzylhemisuccinate resulting from a Stobbe condensation with an appropriate aromatic aldehyde, followed by catalytic hydrogenation of the intermediate α-benzylidene hemisuccinic ester, was resolved by means of a chiral base (ephedrine or α-methyl benzylamine).Reduction of each enantiomer, using calcium borohydride, then led to the corresponding optically active β-benzyl-γ-butyrolactone.In this way, the following two lactones were obtained in both (R)-(+) and (S)-(-) enantiomeric forms, β-piperonyl- and β-veratryl-γ-butyrolactones 1 and 2 respectively.These lactones were used as key-intermediates for the syntheses of 17 optically active lignans and lignoids, such as (-)-dimethylmatairesinol (-)-23, (-)-kusunokinin (-)-26 and (+)-dimethylisolariciresinol (+)-35.