Quantitative Monitoring of Solid-Phase Synthesis Using Gated Decoupling 13C NMR Spectroscopy with a 13C-Enriched Protecting Group and an Internal Standard in the Synthesis of Sialyl LewisX Tetrasaccharide

Just tagging along. For the nondestructive quantitative monitoring of solid-phase oligosaccharide synthesis a ¹³C-enriched tag (*) was incorporated in the linker and a ¹³C-enriched protecting group (⧫) was included in the growing molecule. By integration of the signals in a gated decoupling ¹³C NMR experiment the reaction progress can be monitored. This method was demonstrated with the synthesis of sialyl Lewis^x tetrasaccharide on a Tentagel support ((P)). Bn=benzyl, PEG=poly(ethylene glycol).