Crystal structure of N-(3-oxobutanoyl)-l-homoserine lactone

Abstract

The structure and absolute configuration of the title compound, C8H11NO4, which is a known quorum-sensing modulator, have been determined. The molecule exhibits signs of an intramolecular attractive carbonyl–carbonyl n→π* interaction between the amide and lactone ester groups, specifically – a short contact of 2.709 (2) Å between the amide oxygen atom and ester carbon atom, approach of the amide oxygen atom to the ester carbonyl group along the Bürgi–Dunitz trajectory, at 99.1 (1)°, and pyramidalization of the ester carbonyl group by 1.1 (1)°. Moreover, a similar n→π* interaction is observed for the amide carbonyl group approached by the ketone oxygen donor. These interactions apparently affect the conformation of the uncomplexed molecule, which adopts a different shape when bound to protein receptors. In the crystal, the molecules form translational chains along the a axis via N—H...O hydrogen bonds.

Keywords

• crystal structure
• homoserine lactone
• carbonyl interaction
• NBO analysis
• hydrogen bonding