Formation of cyclic ethers in the double Baeyer-Villiger oxidation of ketals derived from cyclic ketones

Abstract

Mass spectra were measured at 25 eV. Thin layer chromatography (TLC) was performed on Merk Kieselgel 60 GF254.

Trifuoroperacetic acid in consecutive Criegee rearrangement and carboxonium ions generation

“…This process is very similar to the above mentioned studies when cyclic ketals were converted into orthocarbonates 27,28 and into lactones. …”

A Multifunctional Monooxygenase XanO4 Catalyzes Xanthone Formation in Xantholipin Biosynthesis via a Cryptic Demethoxylation

“…Despite successful synthesis of polycyclic xanthone antibiotics (Knueppel et al, 2015;Kelly et al, 1989;Walker et al, 2005), direct oxidative replacement of the carbonyl group in anthraquinone, resulting in xanthone ring formation, has not been reported to date. Similar chemical oxidative replacement of the carbonyl group Yamada, 1984, 1985;Bailey and Bischoff, 1985;Bailey and Shih, 1982) required a complex substrate structure and multistep synthesis. The enzymatic construction of the xanthone ring demonstrated here suggests a potentially powerful alternative approach and may inspire new greener chemical or chemoenzymatic routes for synthesis of xanthone intermediates in order to address the growing demand for novel chemotherapeutic agents.…”

New transformation of cycloalkanone acetals by peracids α,ω-dicarboxylic acids synthesis

“…The authors [7,8] failed to synthesize the expected products of the Baeyer-Villiger rearrangements under action of MCPBA on cycloalkanone acetals with the cycle size more than six carbon atoms.…”

“…The oxidation of acetals (obtained from cyclic ketones) under action of peracids was investigated in a small number of works [7][8][9][10][11]. Practically all of these works describe the reaction with participation of MCPBA as oxidative agent.…”

“…Practically all of these works describe the reaction with participation of MCPBA as oxidative agent. Orthocarbonates and cyclic ethers [7,8], optically active lactones [9], and orthoesters [10] were obtained depending on conditions of the oxidation and acetal structures. The cyclic acetals with oxygen in cycle were transformed into lactones [11] by MCPBA in the presence of boron trifluoride.…”