A chemical toolkit for sulfofucose metabolism: Scalable access to sulfofucose and sulfofucolytic intermediates

Sulfosugars are organosulfur metabolites that contribute to global sulfur cycling, yet the metabolism of the rarer sulfofucose (SFuc) remains poorly defined, in part due to limited access to authentic standards. We report a scalable five-step synthesis of SFuc from D-galactose, including a uniformly 13 C 6 -labelled isotopologue, and the preparation of defined and putative sulfofucolytic intermediates: sulfogalactonate, sulfotagatose, and sulfotagatose-1-phosphate. Single-crystal X-ray diffraction was crucial for redefining the composition of a tagatose–uronate calcium salt, enabling its reliable use as an intermediate en route to sulfotagatose. Chemoenzymatic phosphorylation furnished sulfotagatose-1-phosphate as a diagnostic standard. Together, these compounds establish a practical chemical toolkit to support pathway assignment, enzyme annotation, and discovery of sulfofucose-degrading bacteria.