With access to a robust glycosylation procedure in place, we sought to complete postglycosylation oxidation of the disaccharide D-Glc component (to D-GlcA) and from there access the required protecting group patterns for CS-A/C/D/E/O. Accordingly, we removed the 6'-O-protecting groups from within disaccharides 19 and 23 (thiourea for AcCl cleavage in 19 and DDQ for oxidative PMB removal in 23). From here oxidative conditions using a biphasic TEMPO/BAIB system were applied to deliver common disaccharides 24 and 25 in 85% and 60% yields respectively (Scheme 4). The lower yield for disaccharide 25 was attributed to a sensitivity of the N-TCA protecting group to excess K2CO3 in the carboxylate methylation step. required alternate reductive ring opening conditions. Sakagami and Hamana previously identified a combination of PhBCl2 and Et3SiH for regioselective ring opening of benzylidene acetals to 4-OBn/6-OH products. Reactions were generally performed in CH2Cl2 at -78 °C with an excess of Et3SiH and PhBCl2. However, in CH2Cl2, when an excess of Et3SiH is used, the silane reduces PhBCl2 to PhBHCl, which can hydroborate alkenes, presenting a potential problem for our anomeric O-allyl moiety. To avoid this, use of only 1.1 equivalents of Et3SiH in CH2Cl2 at low temperatures has been reported. Upon adopting these conditions for disaccharide 24 for 20 minutes all starting material was consumed and there was no notable side product formation by TLC analysis. Subsequent C6-O-benzoylation of the crude material delivered disaccharide 27 in 73% over two steps. NMR analysis confirmed orthogonal 4-O-/6-O-protecting group patterns in both 26 and 27 (illustrated for 27 in Figure ). Lastly, acidic cleavage of the benzylidene acetal within disaccharide 25 afforded 28 as a precursor to CS-C, CS-E and CS-O. To exemplify the utility of our approach we completed a formal synthesis of a CS-C disaccharide (Scheme 4, green box). 6-O-Sulfation of disaccharide 28 using 2.5 equivalents of SO3 . NMe3 was achieved in 94% yield. Deprotection of all esters and the N-TCA group was completed using standard conditions, followed by a final N-acetylation to deliver regiospecifically sulfated disaccharide 29 in 19% yield over three steps.