General Method for the Synthesis of (-)-Conduritol C and Analogs from Chiral Cyclohexadienediol Scaffolds

An efficient and facile general method for the synthesis of conduritol C analogs, taking advantage of an enantioselective biocatalysis process of monosubstituted benzenes, is described. The absolute stereochemical patterns of the target molecules (−)-conduritol C, (−)-bromo-conduritol C, and (−)-methyl-conduritol C were achieved by means of chemoenzymatic methods. The stereochemistry present at the homochiral cyclohexadiene-cis-1,2-diols derived from the arene biotransformation and the enantioselective ring opening of a non-isolated vinylepoxide derivative permitted the absolute configuration of the carbon bearing the hydroxyl groups at the target molecules to be established. All three conduritols and two intermediates were crystallized, and their structures were confirmed by X-ray diffraction. The three conduritols and intermediates were isostructural. The versatility of our methodology is noteworthy to expand the preparation of conduritol C analogs starting from toluene dioxygenase (TDO) monosubstituted arene substrates.

Benzoate dioxygenase fromRalstonia eutrophaB9 – unusual regiochemistry of dihydroxylation permits rapid access to novel chirons

Oxidation of benzoic acid by a microorganism expressing benzoate dioxygenase leads to the formation of an unusualipso,orthoarenecis-diol in sufficient quantities to be useful for synthesis.

Regio- and stereospecific synthesis of a new benzoconduritol-C derivative

A stereospecific synthesis of 3-(2-bromophenoxy)-1,2,3,4-tetrahydronaphthalen-1,2,4-triol (benzoconduritol-C derivative) has been achieved by a fully regio- and stereospecific rhodium catalysed reaction of oxabenzonorbornadiene in the presence of 2-bromophenol.

Concise chemoenzymatic synthesis of epi-inositol

epi-Inositol was synthesized in six steps in 40% overall yield from a bacterial bromobenzene metabolite. The chemoenzymatic route involved toluene dioxygenase oxidation, substrate-directed catalytic osmylation, m-CPBA epoxidation, radical debromination, and Amberlite-catalized hydrolysis. The route described is amenable to scaleup and could allow access to cis-inositol, and deoxy derivatives of epi-inositol.