tert-Butyl (2S)-2-{3-[(R)-bis-(tert-but-oxy-carbon-yl)amino]-2-oxopiperidin-1-yl}-3-methyl-butano-ate.

The title compound, C(24)H(42)N(2)O(7), is a chiral lactam-constrained amino acid with a six-membered ring backbone and isopropyl and tert-butyl ester side chains. The conformation of the six-membered ring can be described as a half chair, with two CH(2) C atoms lying 0.443 (1) and -0.310 (1) Å out of the best plane of the other four atoms (mean deviation = 0.042 Å). Both N atoms are sp(2) hybridized, lying 0.0413 (9) and 0.067 (1) Å out of the planes defined by the three C atoms bonded to them. The absolute configuration was determined, based on resonant scattering of light atoms in Cu Kα radiation.