Synthesis of 5-aminopentyl 4,6-O-[(R)-1-carboxyethylidene]-beta-D-galactopyranoside and its use as a ligand for the affinity chromatography of human serum amyloid P . protein.

A series of 2,3-di-O-benzoyl-D-galactopyranosides, alpha-allyl (5), alpha-benzyl (6), beta-ethyl-1-thio (7), beta-phenyl-1-thio (8), and alpha-methyl (9),were prepared from the corresponding 4,6-O-benzylidene derivatives and were acetalated in acetonitrile with methyl pyruvate, to give diastereoselectively the 2,3-di-O-benzoyl-4,6-O-[(R)-1-methoxycarbonylethylidene]-D- galactopyranosides 10-16. The latter were converted into the 2,3-di-O-benzoyl-4,6-O-[(R)-1-methoxycarbonylethylidene]-D-galacto pyranosyl alpha- and beta-trichloroacetimidates 19 and 20, alpha- and beta-fluorides 21 and 22, the alpha-bromide 23, and the alpha-chloride 24, respectively. These donors, including the phenyl 1-thiogalactoside 14, reacted with 5-[(benzyl-oxycarbonyl)amino]pentanol to give the corresponding protected beta-D-galactoside 27, deblocking of which afforded the title compound 1. Binding of 1 to epoxypropyl-modified acrylamide beads gave an affinity adsorbent that was used to isolate serum amyloid P protein from human serum.