Microbial Baeyer-Villiger oxidations

Figure 1.53 shows the Fluka (kilogram-scale) asymmetric microbial Baeyer-Villiger oxidation of racemic bicyclo[3.2.0]hept-2-en-6-one (X) using a 50 L bioreactor as described in a publication by Wohlgemuth et alP ... 

Hilker, I., Wohlgemuth, R., Alphand, V. and Eurstoss, R. Microbial Transformations 59 First Kilogram Scale Asymmetric Microbial Baeyer-Villiger Oxidation with Optimized Productivity Using a Resin-based in situ SFPR Strategy. Biotechnol. Bioeng. 2005, 92, 702-710. 

Mihovilovic MD, Rudroff F, Winninger A, Schneider T, Schulz F, Reetz MT (2006) Microbial Baeyer-Villiger oxidation Stereopreference and substrate acceptance of cyclohexanone monooxygenase mutants prepared by directed evolution. Org Lett 8 1221-1224... 

Scheme 21.7 Microbial Baeyer-Villiger oxidation of prochiral cyclobutanones to access antipodal butyrolactones as a platform for the synthesis of various lignans.

Scheme 2.163 Microbial Baeyer-Villiger oxidation of a bicyclic ketone involving classic resolution...

Scheme 2.164 Enantiodivergent microbial Baeyer-Villiger oxidation involving nonclassic resolution...

Mihovilovic and coworkers have utilized a microbial Baeyer-Villiger oxidation to desymmetrize readily available 8-oxabicyclo[3.2.1]octene 218. Their key reaction used E. coli in a whole-cell oxidation to give multi-gram quantities of 219 in high optical purity (Scheme 59) [67], To demonstrate its utility they transformed 219 into 220, 221, and 222 thus intercepting intermediates that had previously been converted into the namral products (+)-trani-kumausyne, goniofufurone, and (+)-showdomycin. 

Hilker I, Wohlgemuth R, Alphand V, Furstoss R. Microbial transformations 59 first kilogram scale asymmetric microbial Baeyer-Villiger oxidation with optimized productivity using a resin-based in situ SFPR strategy. Biotechnol. Bioeng. 2005 92 702-710. 

Bacteriological sulfur, 23 577-578 Bacteriophages, 3 135 12 474 in fermentation, 11 46 Bacteriorhodopsin, 20 826, 840 photochromic material, 6 603 Bacteriosins, 12 76. See also Bacteriocins Bacteriostatic water, 18 714 Bacterium lactis, 11 7 Baculovirus expression system, 5 346 Baddeleyite, 21 489 26 623-624 colorants for ceramics, 7 346t Badische Anilin und Soda Fabrik (BASF) terpenoid manufacture process, 24 481 Baeyer-Villiger oxidation reactions, 14 592 chiral recognition by enzymes, 3 675 microbial, 16 401 Baffled shellside flow, 13 262 Baffles, in stirred tank geometries,... 

Schwab W, Dambach P, Buhl HJ. Microbial degradation of heptenophos in the soil environment by biological Baeyer-Villiger oxidation. J. Agric. Food Chem. 1994 42 1578-1583. 

The mono-oxygenases which catalyse a series of oxidations such as hydroxylation, epoxidation, heteroatom oxidation and Baeyer-Villiger oxidation (Figure 2.24), depend on NADH or NADPH and cofactors usually Fe or Cu. A particularly important reaction is the direct incorporation of molecular oxygen into non-activated carbon centres, such as in synthesis of important steroidal drags by microbial 11 dr-hydroxylation of... 

Hilker, L, Alphand. V., Wohlgemuth, R. and Furstoss, R. (2004) Microbial transformations 56. Preparative scale asymmetric Baeyer-Villiger oxidation using a highly productive two-in-one ... 

The microbial reaction sequence to testololactone (24) involves an intermediate ester 23 from the first Baeyer-Villiger oxidation that ordinarily undergoes hydrolysis by the esterases present in the fermentation environment. However, the tendency of the ester to undergo hydrolysis and further conversion can be blocked by the use of the potent esterase inhibitor diisopropylfluorophosphate. Most of the reported work417-421 with steroids is concerned with the oxidation of 22 to acetate 23. 

Other microbial strains capable of carrying out Baeyer-Villiger oxidations on steroids are Fusarium lint IFO 7156443, Fusarium solani413, Hwnicola sp.447, Paecilomyces sp.44S and Peni-cillium lilacinum NRRL 895416. The substrate specificity can be broadened by the use of a purified enzyme from Cylindrocarpon radicicola in this case several other steroids are oxidized422 423. 

Enzymatic conversion of ketones to esters is very common in microbial degradations. A synthetically important as well as typical transformation is the enzymatic Baeyer-Villiger oxidation, reported by Walsh,... 

SCHEME 36.13. Selected examples of asymmetric Baeyer-Villiger oxidations catalyzed by microbial... 

---