Five Roads That Converge at the Cyclic Peroxy-Criegee Intermediates: BF3‑Catalyzed Synthesis of β‑Hydroperoxy-β-peroxylactones

• Published in: Journal of organic chemistry Vol. 83; no. 21; pp. 13427 - 13445
• Main Authors: Vil’, Vera A, Gomes, Gabriel dos Passos, Ekimova, Maria V, Lyssenko, Konstantin A, Syroeshkin, Mikhail A, Nikishin, Gennady I, Alabugin, Igor V, Terent’ev, Alexander O
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 02.11.2018; Amer Chemical Soc
• Subjects: acetates; chemical structure; Chemistry; Chemistry, Organic; enols; hydrogen peroxide; organic chemistry; oxidation; Physical Sciences; potential energy; roads; Science & Technology; silyl enol ethers; thermodynamics; HIGHLY EFFICIENT CATALYST; ELECTROORGANIC CHEMISTRY; ORGANIC PEROXIDES; BAEYER-VILLIGER REACTION; SILYL ENOL ETHERS; BRIDGED 1,2,4,5-TETRAOXANES; HYDROGEN-PEROXIDE; MALONYL PEROXIDES; PERACID OXIDATION; BORON-TRIFLUORIDE PVPP-BF3
• ISSN: 0022-3263; 1520-6904; 1520-6904
• DOI: 10.1021/acs.joc.8b02218

We have discovered synthetic access to β-hydroperoxy-β-peroxylactones via BF3-catalyzed cyclizations of a variety of acyclic precursors, β-ketoesters and their silyl enol ethers, alkyl enol ethers, enol acetates, and cyclic acetals, with H2O2. Strikingly, independent of the choice of starting material, these reactions converge at the same β-hydroperoxy-β-peroxylactone products, i.e., the peroxy analogues of the previously elusive cyclic Criegee intermediate of the Baeyer–Villiger reaction. Computed thermodynamic parameters for the formation of the β-hydroperoxy-β-peroxylactones from silyl enol ethers, enol acetates, and cyclic acetals confirm that the β-peroxylactones indeed correspond to a deep energy minimum that connects a variety of the interconverting oxygen-rich species at this combined potential energy surface. The target β-hydroperoxy-β-peroxylactones were synthesized from β-ketoesters, and their silyl enol ethers, alkyl enol ethers, enol acetates, and cyclic acetals were obtained in 30–96% yields. These reactions proceed under mild conditions and open synthetic access to a broad selection of β-hydroperoxy-β-peroxylactones that are formed selectively even in those cases when alternative oxidation pathways can be expected. These β-peroxylactones are stable and can be useful for further synthetic transformations.