• Journal of the Korean Chemical Society
• /
• v.58 no.2
• /
• pp.193-197
• /
• 2014

Dibenzo-18-crown-6, dibenzo-21-crown-7 and dihydroxy dibenzo-18-crown-6 were synthesized by Bayer-Villiger oxidation strategy. Dibenzo-18-crown-6 and dibenzo-21-crown-7 could be synthesized through a three-step protocol starting from salicylaldehyde. Salicylaldehyde was reacted with bis-(2-chloroethyl)ether using $K_2CO_3$ in acetonitrile to link the two phenolic groups with the oxyethylene bridge followed by conversion of the formyl group to the hydroxy group via a Baeyer-Villiger reaction and finally linking the two phenolic group with appropriate oxyethylene bridge. The two target crown ethers were obtained in overall yield, 24% and 30%, respectively. This method has a great potential for synthesis of symmetrical as well as unsymmetrical dibenzo crowns with varying oxyethylene bridges. Baeyer-Villiger oxidation could be used to prepare dihydroxy derivative of dibenzo-18-crown-6 through acetylation of dibenzo-18-crown-6 followed by Baeyer-Villiger oxidation. The Baeyer-Villiger oxidation could be substantially accelerated using trifluoroacetic acid.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.7
• /
• pp.1083-1089
• /
• 2007

Because of their selectivity and catalytic efficiency, BVMOs are highly valuable biocatalysts for the chemoenzymatic synthesis of a broad range of useful compounds. In this study, we investigated the microbial Baeyer-Villiger oxidation and sulfoxidation of thioanisole and bicyclo[3.2.0]hept-2-en-6-one using whole Escherichia coli cells that recombined with each of the Baeyer-Villiger monooxygenases originated from Pseudomonas aeruginosa PAOl and two from Streptomyces coelicolor A3(2). The three BVMOs were identified in the microbial genome database by a recently described protein sequence motif; e.g., BVMO motif(FXGXXXHXXXW). The reaction products were identified as (R)-/(S)-sulfoxide and 2-oxabicyclo/3-oxabicyclo[3.3.0]oct-6-en-2-one by GC-MS analysis. Consequently, this study demonstrated that the three enzymes can indeed catalyze the Baeyer-Villiger reaction as a biocatalyst, and effective annotation tools can be efficiently exploited as a source of novel BVMOs.

• Journal of Applied Biological Chemistry
• /
• v.64 no.4
• /
• pp.433-438
• /
• 2021

Polyethylene is widely used as an agricultural film, but eco-friendly technology is lacking for its decomposition. Thus, recently, much attention has been paid to develop a technology for biological polyethylene decomposition. It has been expected that several oxidation steps will be required in the biological degradation of polyethylene. First, secondary alcohol is formed on the polyethylene chain, and then the alcohol is oxidized to a carbonyl group. In the subsequent process, the carbonyl group is converted to an ester by Baeyer-Villiger monooxygenase (BVMO), and this ester bond is expected to be cleaved by lipase and esterase in the final step. In this work, we reviewed BVMO as one of the promising enzymes for polyethylene decomposition, in terms of its reaction mechanism, classification, and engineering. In addition, we also give a brief perspective on polyethylene decomposition using BVMO.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.6
• /
• pp.832-837
• /
• 2012

The oxidative potential of the fungus Penicillium brasilianum, a strain isolated as endophytic from a Meliaceae plant (Melia azedarach), was investigated using 1-indanone as substrate to track the production of monooxygenases. The fungus produced the dihydrocoumarin from 1-indanone with the classical Baeyer-Villiger reaction regiochemistry, and (-)-(R)-3-hydroxy-1-indanone with 78% ee. Minor compounds that had resulted from lipase and SAM activities were also detected. The biotransformation procedures were also applied using a collection of Penicillium and Aspergillus fungi obtained from M. azedarach and Murraya paniculata. The results showed that Baeyer-Villiger were mostly active in fungi isolated from M. azedarach. Almost all fungi tested produced 3-hydroxy-1-indanone.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.12
• /
• pp.1685-1689
• /
• 2014

Baeyer-Villiger (BV) oxidation of cyclohexanone to ${\varepsilon}$-caprolactone in a microbial system expressing cyclohexanone monooxygenase (CHMO) can be influenced by not only the efficient regeneration of NADPH but also a sufficient supply of oxygen. In this study, the bacterial hemoglobin gene from Vitreoscilla stercoraria (vhb) was introduced into the recombinant Escherichia coli expressing CHMO to investigate the effects of an oxygen-carrying protein on microbial BV oxidation of cyclohexanone. Coexpression of Vhb allowed the recombinant E. coli strain to produce a maximum ${\varepsilon}$-caprolactone concentration of 15.7 g/l in a fed-batch BV oxidation of cyclohexanone, which corresponded to a 43% improvement compared with the control strain expressing CHMO only under the same conditions.

• Bulletin of the Korean Chemical Society
• /
• v.18 no.7
• /
• pp.754-760
• /
• 1997

Through a sequence of reactions including Diels-Alder cycloaddition of a furan diene as the key step, 11-oxatricyclo[6.2.1.01,6]undecyl rings were synthesized from 5-methylfurfural with the goal of developing a synthetic protocol to 11-oxabicyclo[6.2.1]undecyl system. The strategy to incorporate an oxygen atom at C6 carbon of tricyclic 11 or 16 by Baeyer-Villiger oxidation was unsuccessful, implicating that there is too much steric congestion around the carbonyl ketone. As an alternative approach, bicyclic 23 and 24 were prepared from 2-methylfuran via known tricyclic 20. Cyclization of bicyclic 23 and 24 under several reaction conditions also failed to produce hydroxylated product 25 and 26.