The chemoenzymatic synthesis of 9-substituted 3,9-dideoxy-d-glycero-d-galacto-2-nonulosonic acids

A series of C-6 functionalised mannosides has been synthesised. Subsequent exposure of 6-azido-6-deoxy-d-mannopyranose and 6-bromo-6-deoxy-d-mannopyranose to Neu5Ac aldolase and sodium pyruvate provided the corresponding 9-azido- and 9-bromo-3,9-dideoxy-d-glycero-d-galacto-2-nonulosonic acid, respectively.