(1R,6R)-1-Methyl-8-aza­spiro­[5.6]dodecan-7-one

The crystal structure of the title compound, C(12)H(21)NO, has been investigated to establish the absolute stereochemistry at position 1. The absolute stereochemistry at the quaternary centre at position 6 is established to be R using an asymmetric Birch reductive alkyl-ation reaction for which the stereochemical outcome is known. The crystal structure indicates the presence of two conformers of the bicyclic (1R,6R)-spiro-lactam ring system that differ in the conformation adopted by the six-membered ring. In one conformer, the meth-yl group adopts an axial position whereas in the other conformer, the same methyl group adopts an equatorial position. In both conformers, the seven-membered ring adopts a chair conformation. The two conformers of the bicyclic spiro-lactam are connected to each other via inter-molecular N-H⋯O hydrogen bonds forming a heterodimer. The asymmetric unit contains two such dimers.