Reducing to non-reducing oligosaccharide synthesis of the Lewis a trisaccharide using an anomeric O-silyl light-fluorous tag.^47,48  Part A: Reagents and conditions (a) imidazole, DMAP, DCM, 85%; (b) MeONa, MeOH, quant.; (c) PhCH(OMe)₂, CSA, MeCN, 75% after 2 cycles; (d) TMSOTf, DCM, 78% after 2 cycles; (e) TBAF, THF, 62%. Part B: Reagents and conditions (a) TEA, DMAP, DCM; (b) MeONa, MeOH, 98%; (c) PhCH(OMe)₂, CSA, MeCN, 86% after 2 cycles; (d) TMSOTf, DCM, −30 °C, 70% after 2 cycles; (e) Et₃SiH (5 eq.), TFA (5 eq.), TFAA (1 eq.), DCM, 86%; (f) TMSOTf (0.1 eq.), DCM, −40 °C, 60% after 2 cycles; (g) TBAF (1.5 eq.), THF, 75%.