Expanding the chiral pool: oxidation of meta-bromobenzoic acid by R. eutrophus B9 allows access to new reaction manifolds

Abstract

Metabolism of meta-bromobenzoic acid by the blocked mutant Ralstonia eutrophus B9 affords an enantiopure dearomatised halodiene-diol which we demonstrate is a versatile chiron for organic synthesis. The presence of the halogen leads to reactivity that is distinct to that observed for the non-halogenated analogue and also serves as a synthetic handle for further functionalisation.

Photooxygenation of a Microbial Arene Oxidation Product and Regioselective Kornblum–DeLaMare Rearrangement: Total Synthesis of Zeylenols and Zeylenones

“…Thus, benzoylation of 43 was followed by reaction with 1 O 2 to afford endoperoxide 45 (Scheme ). The required zeylenol stereochemistry arises due to the selective approach of the dienophile to the face opposite to that bearing the acetonide 31a. 32, 43…”

“…[15] stereoselective fashion, with the sense of enantioinduction being conserved across organisms and substrates [29] (Scheme 2a, ortho, meta oxygenation). In contrast, organisms that express benzoate dioxygenase [30] (BZDO) oxidise benzoic acids [31] in a process that exhibits not only different regioselectivity, but also the opposite absolute sense of enantioinduction (Scheme 2b, ipso, ortho oxygenation). cis Diol 38 and its substituted analogues have been comparatively underexploited in synthesis so far.…”

Chemoenzymatic Synthesis of Triazololactams Structurally Related to Pancratistatin

“…Protection yielded compound 12 , which reacted with a symmetric alkyne to give the intermolecular Huisgen cycloaddition product, triazole 13 , in high yield (Scheme , route 2). Interestingly, the catalyzed version of the Huisgen reaction was also used on chiral derivatives of cyclohexadiene diols by Lewis et al to render a chiral triazole carboxylic acid methyl ester from the corresponding alkyne.…”

Applications of biocatalytic arene ipso,ortho cis-dihydroxylation in synthesis

“…In the event, we found formation of 3-bromo isomer 87 to be greatly favoured over 5-bromo isomer 88. 23 Although turnover of 86 was much lower than for unsubstituted benzoate, sufficient quantities were nevertheless produced to demonstrate its utility in synthesis. Protection of 87 as acetonide ester 89 and complexation with iron tricarbonyl afforded facial isomers 90 and 91, but no rearrangement to a product analogous with 77 was observed.…”