Simple formylacetal (CH₂) as a novel linker for saccharide synthesis on soluble-polymer support

Described herein is a new formylacetal (CH₂) linker for immobilization of small molecules onto a soluble-polymer support, poly(ethylene glycol) ω-monomethyl ether (MPEG), and its application to saccharide synthesis. This small linker allows immobilization of a hindered hydroxy group such as the 4-hydroxy group of glucose onto MPEG. The linker is stable under several reaction conditions including glycosylation. Removal of this support was found to be achieved through cleavage of the CH₂ linker either by a Lewis acid (TMSI or Ce(OTf)_x) or a Brønsted acid (trifluoroacetic acid) in moderate to good yields. In combination with solid acid catalyst, simpler operations became possible during the working-up and purification processes.