Enzymatic dihydroxylation

Hudlicky T, Gonzalez D, Gibson DT (1999) Enzymatic Dihydroxylation of Aromatics in Enantioselective Synthesis Expanding Asymmetric Methodology. Aldrichimica Acta 32 35... 

Versatile epoxyquinol intermediates were conveniently accessed via metabolites derived from the enzymatic dihydroxylation of bromobenzene [172]. The chemoen-zymatic approach led to shortened total syntheses of several epoxyquinols derived... 

Fabris F, Collins J et al (2009) Investigation of steric and functionality limits in the enzymatic dihydroxylation of benzoate esters. Versatile intermediates for the synthesis of pseudo-sugars, amino cyclitols, and bicyclic ring systems. Org Biomol Chem 7 2619-2627... 

Enzymatic dihydroxylation of toluene by Pseudomonas putida affords (-t-)-cis-l, 2-dihy-droxy-3-methyl-3,5-cyclohexadiene) (Figure 33). The relative stereochemistry was determined to be ds, but the absolute configuration was unknown, until determined by Ziffer et al. [43] Catalytic reduction of the diene gave a stereochemically well-resolved cyclohexane diol suitable for introducing the benzoate chromophore. The dibenzoate gave a (-) exciton chirality CD, and thus the organism produces the diene-diol shown in Figure 33(a). 

Hudlicky, T., Gonzalez, D., and Gibson, D. T. 1999. Enzymatic dihydroxylation of aromatics in enantioselective synthesis expanding asymmetric methodology. Aldrichimica Acta, 32(2), 35-62. 

So-NCC-2 (25b), the most abundant of the five NCCs detected in spinach, had the same constitution as the catabolite from barley, Hv-NCC-1 (2) (51). Both of these isomeric NCCs can result (in a formal sense) from an enzymatic dihydroxylation at the vinyl group at ring A. With osmium tetroxide, the catabolite Cj-NCC-1 (23) (or its methyl ester 29) was stereo-unselectively dihydroxylated at the corresponding vinyl group. One of the dihydroxylation products of 23 proved to be identical with So-NCC-2 (25b), whose configuration at C(l) thus differed from that of Hv-NCC-1 (2) (see Scheme 13) (51). 

The development of enzymatic dihydroxylation of aromatics has enabled synthetic access to a large collection of cyclohexadiene diols in enantiopure form. 

SCHEME 15.7 Myers synthesis of (-)-doxycycline (46) using an enzymatic dihydroxylation. 

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