Related Experiment Video
Updated: May 19, 2026

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
(S)-2-Oxotetra-hydro-furan-3-aminium bromide
Jace D Sandifer1, Frank R Fronczek, Steven F Watkins
1Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803-1804, USA.
Abstract:
In the title HBr salt of (S)-homoserine lactone, C(4)H(8)NO(2) (+)·Br(-), the five-membered ring has an envelope conformation, with the -CH(2)- 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.
Related Concept Videos
Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview
Diazonium Group Substitution: –OH and –H
Hydroboration-Oxidation of Alkenes
Preparation of 1° Amines: Hofmann and Curtius Rearrangement Mechanism
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Preparation of Amines: Reductive Amination of Aldehydes and Ketones
![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
