Synthesis of thio-functionalized carbohydrates and alkene-linker for photo-click immobilization; a) 2- bromoethanol, BF3·Et2O, DCM, 0 °C, 23 h; b) KSAc, DMF, 45 °C, 17 h (72 %); c) NaOMe, MeOH, rt, 3 h (quant.); d) 2-bromoethanol, BF3·Et2O, DCM, −40 °C, 22 h (67 %); e) KSAc, DMF, 45 °C, 7 h (56 %); f) NaOMe, MeOH, rt, 4 h (70 %); g) NaOH, DMF, 45 °C, 2 h (30 %); h) TsCl + KOH, DCM, 0 °C, 5 h (quant.); i) NaN3 + TBAI, DMF, 45 °C, 22 h (77 %); j) PPh3, THF + H2O, 0 °C, 24 h (32 %).