Scheme 2.

(A) Synthesis of Thiol-Derivatized Trehalose 5^37,37a; (B) Synthesis of Thiol-Derivatized Maltose 10^b; and (C) Synthesis of TEG-Disulfide^c

^a(a) PhCH(OCH₃)₂, PTS, DMF, 23 °C, overnight; (b) triethylamine, acetic anhydride, DMF, 23 °C, overnight (38% overall yield); (c) NBS, CaCO₃, CCl₄, 77 °C, 3 h (91%); (d) KI, DMF, 90 °C, 5 h; (e) KSAc, DMF, N₂, 8 h (66% overall yield); (f) NaOCH₃, methanol, 23 °C, 6 h; (g) Amberlight IRC-120 H⁺ resin, pH 7; and (h) DTT, MeOH, 23 °C, 8 h (22%). ^b(a) Acetic anhydride, pyridine, 23 °C, 36 h (80%); (b) BF₃·Et₂O, dichloromethane, 2-bromoethanol, −40 °C, 1 h; (c) 23 °C, 22 h; (d) KI, DMF, 70 °C; (e) KSAc, DMF, 23 °C, 8 h; (f) NaOCH₃, methanol, 23 °C, 6 h; (g) pH 7; and (h) DTT, 23 °C, 8 h. ^c(a) NaI, DMF, 90 °C, 2 h; (b) KSAc, DMF, 80 °C, 6 h; (c) K₂CO₃, methanol, 3 h; and (d) titration with saturated I₂/ethanol.