Fig. 4.
Global deprotection allowing access to target oligosaccharides. Reagents and conditions: a H2NNH2.HOAc, MeOH/DCM 5:2, RT, overnight; b TREAT-HF, THF, reflux, 24 h, 92% (over two steps); c H-Cube, 20% Pd(OH)2/C, HCl (2.0 equivalents), 10 bars, 40 °C, MeOH/DCE, 78% (for 4); 78% (for 3); d NaOMe, MeOH/DCM 2:1, RT, overnight; e TBAF, THF, 0 °C to RT, overnight, 89% (over two steps); f Pd black, H2, HCl (1.0 equivalent), MeOH/DCE, quant. (for 1, 2, 5, 6, and 7). TBAF tetrabutylammonium fluoride, TREAT-HF triethylaminetrihydrofluoride