Influ-ence of the 4,6- O -Benzylidene, 4,6- O -Phenylboronate, and 4,6- O -Polystyrylboronate Protecting Groups on the Stereochemical Outcome of Thioglycoside-Based Glycosylations Mediated by 1-Benzenesulfinyl Piperidine/Triflic Anhydride and N -Iodosuccinimide/Trimethylsilyl Triflate.