ASYMMETRIC SYNTHESIS AND ABSOLUTE CONFIGURATION OF 1-α-PHENYLETHYL-2,5-DIMETHYL-4-PIPERIDONE ISOMERS

Article abstract of DOI:10.1007/BF00474353

Reaction of the methyl iodide of trans-1,2-5-trimethyl-4-piperidone with S-α-phenylethylamine proceeds asymmetrically and leads in 66percent optical yield to the formation of the cis- and trans-diastereomeric pair of 1-(α-phenylethyl)-2,5-dimethyl-4-piperidone, in which the new asymmetric centers possess the 2S,5S- and 2S,5R-configurations, respectively.According to x-ray structural analysis, the minor trans-1-(α-phenylethyl)-2,5-dimethyl-4-piperidone component possesses the 2R,5S-configuration.The occurrence of asymmetric synthesis accompanying transamination was confirmed via the preparation of enantiomers of trans-2,5- and trans-1,2,5-trimethyl-4-piperidones.