Mechanistic aspects of the fluorination of cyclohexane and cyclohexene with acetyl hypofluorite in acetic acid

Abstract

The reaction of acetyl hypofluorite in acetic acid with both cyclohexane and cyclohexene has been investigated. Analysis by GCMS and radio‐HPLC, using 18F as a tracer, revealed that, apart from typical products expected from a radical reaction, several compounds originating from carbocationic intermediates were formed. On the basis of the observed products, a single‐electrontransfer (SET) mechanism leading to an intermediate radical‐cation is proposed.

Synthesis of Optically Active Vicinal Fluorohydrins by Lipase-Catalyzed Deracemization

“…Spectroscopic data agree with published data. 28 trans-1-Acetoxy-2-fluorocycloheptane 3b: yield 0.81 g ,9.10. Found: C,63.57;H,9.38.…”

“…trans -1-Acetoxy-2-fluorocyclohexane 3a: yield 0.73 g (91%). Spectroscopic data agree with published data …”

“…trans-2-Fluorocyclohexanol 2a: yield 1.63 g (69%); mp 23-24 °C (lit. 7 20), 73 (4), 72 (13), 69 (9), 67 (28), 58 (9), 57 (100).…”

“…Spectroscopic data agree with published data. 28 trans-1-Acetoxy-2-fluorocycloheptane 3b: yield 0.81 g (93% Chloroacetylation of Fluorohydrins 2. A solution of the fluorohydrin 2 (1 mmol) and chloroacetic anhydride (0.17 g, 1 mmol) was heated to 80 °C for 8 h. After being cooled to room temperature, the mixture was dissolved in diethyl ether (5 mL) and poured into water (8 mL).…”

Selective Fluorinations by Reagents Containing the OF Group

“…However, identifiable factors such as high temperatures and nonpolar solvents, and frequently unidentified ones such as minor impurities, can trigger radical decomposition of AcOF and change the course of the reaction. Visser 69 described the formation of a complicated mixture when reacting cyclohexene with acetyl hypofluorite. All compounds which he identified, including the above-described adduct, were obtained in very low yields.…”