An efficient fructose-1,6-bisphosphate aldolase mediated synthesis of new aminocyclitol analogues of valiolamine is described. The one-pot process where four stereocentres are created involves the formation of two carbon–carbon bonds. One is catalysed by the aldolase, coupling dihydroxyacetone phosphate to nitrobutyraldehydes. The other is the result of a highly stereoselective intramolecular Henry reaction occurring on the intermediate nitroketones. Depending on the configuration of the hydroxyl which is a to the nitro group, two series of configuration are accessible.
The total synthesis of cyclotheonamide C (3), a macrocyclic pentapeptide incorporating an α-keto homoarginine (k-Arg) and a vinylogous dehydrotyrosine (V-ΔTyr) unit, has been achieved.
A highly stereoselective method for the preparation of nitro and aminocyclitols, using fructose-1,6-bisphosphate aldolase, which catalyzes the aldol reaction of dihydroxyacetone phosphate (DHAP) on hydroxynitrobutanals, is reported.
