Stereochemistry of the products of reductive amination of 2,6-bis[(2-oxocyclohexyl)methyl]cyclohexanone, an alicyclic 1,5,9-triketone

The reductive amination of alicyclic 1,5,9-triketone—2,6-bis[(2-oxocyclohexyl)methyl]cyclohexanone—has been studied under Leuckart reaction conditions and in the presence of NaBH3CN. A mixture of diastereomers of quinolizidine structure (2,3,5,6-bistetramethylenehexahydrojulolidine) is obtained. The stereochemistry of seven isomers is determined by the study of their NMR spectra using 2D NMR experiments (1H–1H COSY, HSQC, and HMBC).