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Updated: Aug 8, 2026
06:18
Syntheses, Crystallization, and Spectroscopic Characterization of 3,5-Lutidine N-Oxide Dehydrate
Published on: April 24, 2018
Cyclic oxonium ions and related structures
1DEPARTMENT OF CHEMISTRY, VANDERBILT UNIVERSITY.
Summary
Researchers prepared and characterized cyclic trialkyloxonium ions using NMR spectroscopy. These studies provide independent evidence for the structure and existence of these important organic compounds.
Area of Science:
- Organic Chemistry
- Spectroscopy
Background:
- Trialkyloxonium ions are reactive intermediates crucial in organic synthesis.
- Previous studies suggested the existence of cyclic trialkyloxonium ions through indirect evidence.
Purpose of the Study:
- To prepare and characterize novel cyclic trialkyloxonium ions.
- To elucidate the structures of these compounds using nuclear magnetic resonance (NMR) spectroscopy.
- To provide independent evidence for the existence and structural integrity of these cyclic oxonium salts.
Main Methods:
- Synthesis of various cyclic trialkyloxonium salts, including hexafluoroantimonate and trifluoroacetate salts.
- Characterization using nuclear magnetic resonance (NMR) spectroscopy in different solvents.
- Structural confirmation through analysis of chemical shifts and coupling constants.
- Chemical degradation studies to further support structural assignments.
Main Results:
- Several cyclic oxonium salts, such as 1,2,5-trimethyltetrahydrofuranium and trans-1-methylperhydrobenzofuranium derivatives, were successfully prepared and isolated as crystalline solids.
- NMR spectra confirmed the cyclic oxonium salt structures, with characteristic downfield shifts for the charged methyl group.
- Identification of 2,2,5-trimethyltetrahydrofuran and 2-ethoxy-2-methyl-5-methoxyhexane provided further evidence for the proposed structures and reactivity.
- Solvolysis reactions demonstrated the susceptibility of the tertiary carbon in the oxonium ion to nucleophilic attack.
Conclusions:
- The study successfully prepared and characterized a series of cyclic trialkyloxonium ions.
- NMR spectroscopy provides robust evidence for the structure and stability of these cyclic oxonium salts.
- The findings offer independent verification of these compounds, complementing prior kinetic, preparative, and stereochemical studies.
![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)
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