(S)-2-Oxotetrahydrofuran-3-aminium bromide

Abstract

In the title HBr salt of (S)-homoserine lactone, C4H8NO2+·Br−, the five-membered ring has an envelope conformation, with the –CH2– C atom adjacent to the N-substituted C atom at the flap position. The four-atom mean plane (r.m.s. deviation = 0.005 Å) of the envelope forms a dihedral angle of 32.12 (9)° with the three-atom flap plane. The distorted square-pyramidal coordination about the anion involves five surrounding cations, with the square base defined by three N—H...Br hydrogen bonds [Br...N = 3.3046 (10), 3.3407 (12) and 3.3644 (13) Å] and near-contact with an H atom attached to C [Br...C = 3.739 (1) Å]. Another Br...C contact of 3.427 (1) Å defines the apex. There is also an N—H...O hydrogen bond present linking the cations.