The absolute structure of an indole alkaloid (+)-cinchonaminone by total synthesis of both (+)-cinchonaminone and its enantiomer was determined. The main focus of the study was the enantioselective synthesis of both enantiomers of a chiral cis-3,4-disubstituted piperidine. We also evaluated monoamineoxidase (MAO) inhibitory activities of these enantiomers. Furthermore, its structurally simplified
Ru-catalyzed cycloisomerization of a 1,3-diene and the alkene of an N-dienyl-2-vinylaniline substrate proceeded smoothly, leading to a 3-exomethylene-2-vinylindole derivative in good yield. This useful synthon was successfully applied to the total synthesis of (±)-cinchonaminone.