Polymer-Supported Synthesis and Automation

116 (2 equiv.), TMSOTf (4 cycles) 2. LiOH, H202 KOH, MeOH 

SCHEME 10.13 Polymer-supported assembly and release of an octasaccharide with a heparin/ HS backbone. DIC, N,N -diisopropyIcarbodii midc Piv, pivaloyl. 

A different nonreducing end block (116) was employed for the final coupling to produce a hexasaccharide and an octasaccharide skeleton (117). Basic treatment enabled the release of the oligomers from the support and also liberated the hydroxyls for the O-sulfonation steps, which was performed according to the regular solution-phase procedure [87], 

SCHEME 10.14 Automated solid-phase assembly and synthesis of HA oligomers. 

SCHEME 10.15 Automated solid-phase synthesis of CS-based hexasaccharides. 

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