Reaction of hypochlorous acid with ketones. Novel Baeyer-Villiger oxidation of cyclobutanone with hypochlorous acid

Oxidizing Ethanol and 2-Propanol by Hypochlorous Acid Generated from Chloride Ions on HxWO3 Photoelectrodes

“…We therefore attribute the increase in yield to the light rather than the <1 °C increase in temperature. Moreover, hypochlorous acid undergoes homolytic bond cleavage with near-UV light to generate the highly reactive Cl• and OH• radicals, both strong oxidants. − While the major absorption maximum of the aqueous chlorine-containing species (i.e., - Cl 2 , HClO, and ClO – ) exists at λ < 300 nm, using longer wavelength light to generate radicals has been previously demonstrated. ,,− The UV–vis spectrum of 20 mM solution of Ca­(ClO) 2 is shown in Figure S17. The 405 nm light output by the LED overlaps with the tail in the absorption band at λ max ≈ 325 nm.…”

Continuous Flow Oxidation of Alcohols Using TEMPO/NaOCl for the Selective and Scalable Synthesis of Aldehydes

“…No lactone formation was observed during the oxidation of the related cyclopentanol 1m . There are a few reports for the oxidation of cyclobutanol with concomitant formation of this γ-lactone under various oxidative conditions, however, little is known about the Baeyer–Villiger oxidation of cyclic ketones to lactones in the presence of HOCl at different pH (4–12) . Hypochlorous acid resembles peroxyacids being both a weak acid and an oxidizing agent.…”

“…There are a few reports for the oxidation of cyclobutanol with concomitant formation of this γ-lactone under various oxidative conditions, 20 however, little is known about the Baeyer–Villiger oxidation of cyclic ketones to lactones in the presence of HOCl at different pH (4–12). 21 Hypochlorous acid resembles peroxyacids being both a weak acid and an oxidizing agent. The driving force is the release of ring strain which accounts for the formation of the lactone product in case of cyclobutanol.…”

An Unusual Uncatalyzed Baeyer−Villiger Oxidation of Cyclobutanones to γ-Lactones by Air and Its Mechanistic Implications

“…For instance, hypochlorous acid is reported to bring about BV oxidation of cyclobutanone, but fails in the cases of cyclopentanones or cyclohexanones. [9] However, BV oxidations of cyclobutanones with H 2 O 2 (30% H 2 O 2 , 2.4Ϫ3.0 equiv., 16 h for completion of reaction) are generally carried out under highly acidic conditions. [10] Testing of the methanol after periods of air exposure similar to those required for the completion of reaction indicated it to be only slightly acidic (pH ഠ 6.6), and the concentration of peracid (performic acid), if any, was extremely low (5 ϫ 10 Ϫ3 ).…”