Deoxysugars via microbial reduction of 5-acyl-isoxazolines: Application tothe synthesis of 3-deoxy-D-fructose and derivatives

6-Acylisoxazolines 3a-d were obtained by 1,3-dipolar cycloaddition from ace toxymethyl vinyl ketone and nitro precursors. Compounds 3a-d were biotransf ormed by Aspergillus niger into a 1:1 mixture of stereomers of 5-dihydroxye thyl isoxazolines (+)-4a-d (anti) and (-)-5a-d (syn). Both stereomers were obtained in good yields and with high optical purities. Carbonyl reduction by Aspergillus niger produces alcohols of R-configuration thus giving an ac cess to D-sugar analogues: Compound (+)-4d was converted to 3-deoxy-D-eryth ro-hexulose and several protected derivatives. Total synthesis of 3-deoxy-n -fructose-6-phosphate was also achieved in two steps and 64% overall yield from (+)-4d.