The (S)-4-alkoxo-2-azetidinecarboxylic acids are optically active Β-lactam derivatives of aspartic acid, which are used as precursors of carbapenem-type antibiotics and poly-Β-aspartates. The crystal structures of three (S)-4-alkoxo-2-azetidinecarboxylic acids with alkyl chains with 10, 12 and 16 C atoms were solved using parallel tempering and refined against the X-ray powder diffraction data using the Rietveld method. The azetidinone rings in the three compounds display a pattern of asymmetrical bond distances and an almost planar conformation; these characteristics are compared with periodic solid-state, gas-phase density-functional theory (DFT) calculations and MOGUL average bond distances and angles from the CSD. The compounds pack along  as corrugated sheets separated by approximately 4.40 Å and connected by hydrogen bonds of the type N - H⋯O.
|Original language||English (US)|
|Number of pages||7|
|Journal||Acta Crystallographica Section B: Structural Science|
|State||Published - 2009|
All Science Journal Classification (ASJC) codes
- Biochemistry, Genetics and Molecular Biology(all)