Fig. 2: Synthesis of the N-pNZ protected glucosamine building blocks 3, 4, 6 and 8.

a 1 HMDS, TMSOTf, MeCN, r.t. 2) PhCHO, Et₃SiH, TfOH, CH₂Cl₂, 0 °C to r.t.; b TFA, TFAA, Et₃SiH, CH₂Cl₂, 0 °C to r.t.; c FmocCl, pyridine, CH₂Cl₂, r.t.; d EDC, DMAP, LevOH, CH₂Cl₂, 0 °C to r.t.; e PhCH(OMe)₂, CSA, MeCN/THF r.t.; f PhBCl₂, Et₃SiH, CH₂Cl₂, −78 °C.