Fructose-6-Phosphate Aldolase as Catalyst for Iminosugar Synthesis

An inspection of the stereochemistry at C-2 for the iminosugars revealed that the reductive amination with Pd/C was highly diastereoselective. Interestingly, as already stated [15, 18, 20, 34], we found that the hydrogen was added to the face opposite to the C-4 hydroxyl group, regardless of the relative stereochemistry of the other substituents. Hence, the stereochemistry observed at C-2 was controlled exclusively by the configuration at C-4. An exception was found for the reductive amination of compound 7. In this case, there was no face selectivity and a circa 1 1 diastereomeric mixture was obtained. 

D-Fructose-6-Phosphate Aldolase as Catalyst for Iminosugar Synthesis 

the use of DHA as a donor substrate continues to generate enormous research expectations because it opens the possibiUty for a wide practical industrial application of this methodology [13], 

Recently, it was been found that RhuA accepts DHA in the presence of boric-borate buffer, presumably by reversible in situ formation of DHA borate ester [39]. Most recently, the group of Wong selected an RhuA mutant enzyme that accepts DHA as a donor [40], 

Most interestingly, two fructose 6-phosphate aldolase isozymes (transaldolase C (TALC) and D-fructose-6-phosphate aldolase (FSA)) were reported from the E. coli genome and characterized in recombinant form [41]. 

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