Cobalt-mediated solid phase synthesis of 3-O-alkynylbenzyl galactosides and their evaluation as galectin inhibitors
Methyl beta-D-galactoside was converted to the corresponding 3,4-O-stannylene acetal, which was selectively benzylated with 3-iodobenzyl bromide and coupled to a polymer-bound propargylic ether via a Sonogashira reaction. The polymer-bound carbohydrate substrate was cleaved from the resin with different carbon nucleophiles in a cobalt-mediated Nicholas reaction. The product 3-O-alkynylbenzyl galac