(a) Ac2O pyridine;
(b) HBr, AcOH/DCM, 0 °C, 2 h; (c) 2-chloro-4-nitrophenol, TBABr,
DCM/NaOH (1:1), rt, 18 h; NaOMe, MeOH, rt, 12 h; d-[U-13C]glucose, 1; penta-O-acetyl-d-[U-13C]glucose, 2; 1-bromo-tetra-O-acetyl-α-d-[U-13C]glucose, 3; 2-chloro-4-nitrophenyl-β-d-[U-13C]glucose, 4; TDP-α-d-[U-13C]glucose, 5; TDP-4-keto-6-deoxy-α-d-[U-13C]glucose, 6; TDP-4-keto-β-l-[U-13C]rhamnose, 7; TDP-β-l-[U-13C]rhamnose, 8; TDP-3-methoxy-β-l-[U-13C]rhamnose, 9; TDP-4-amino-6-deoxy-α-d-[U-13C]glucose, 10; TDP-4-hydroxyamino-6-deoxy-α-d-[U-13C]glucose, 11.