(-)-吲哚里西啶167B和(+)-毒芹碱的不对称合成

The enantioselective syntheses of (-)-indolizidine 167B and (+)-coniine were described based on the asymmetric hydrogenation of racemic δ-hydroxy esters via kinetic resolution. With optically active chiral δ-hydroxy ester [1]-4 and chiral 1, 5-diol [1]-5 obtained by asymmetric hydrogenation of racemic ethyl 5-hydroxyoctanoate (rac-4) with chiral spiro iridium catalyst Ir-[1]-SpiroPAP as chiral starting materials, the efficient enantioselective syntheses of (-)-indolizidine 167B and (+)-coniine were achieved by using intramolecular reductive amination and N-substitution/cyclization, respectively, as a key step to construct the chiral aza-bicyclic[4.3.0]nonane skeleton and chiral piperidine ring. This provides new efficient methods for enantioselective syntheses of indolizidine and piperidine alkaloids.