Gram-scale chemoenzymatic synthesis of LeaβProN3 (5). Enzyme abbreviations: SpGalK, Streptococcus pneumoniae galactokinase; BiGalHexNAcP, Bifidobacterium infantis Dgalactosyl-β1–3-N-acetyl-D-hexosamine phosphorylase; BfFKP, Bacteroides fragilis strain NCTC9343 bifunctional L-fucokinase/GDP-fucose pyrophosphorylase; PmPpA, Pasteurella multocida inorganic pyrophosphatase; Hp3/4FT, Helicobacter pylori α1–3/4-fucosyltransferase.