169962-10-1Relevant articles and documents
Synthesis of Pyruvated Saccharide Fragments Related to the Aggregation Factor of the Marine Sponge Microciona prolifera
Ziegler, Thomas
, p. 949 - 956 (2007/10/02)
Treatment of phenyl 2,3,6,2',3'-penta-O-benzoyl-1-thio-β-D-lactoside (7) with BF3 in methyl pyruvate afforded the corresponding phenyl 4',6'-O--1-thio-β-D-lactoside (9) in 91percent yield.The latter was converted via bromide 10 into the corresponding lactal 11 the azidonitration of which afforded an unseparable mixture of the "gluco"- and "manno"-configurated azido nitrates 12 (97percent).As an alternative, benzyl O-(β-D-galactopyranosyl)-(1-->4)-2-azido-2-deoxy-α-D-glucopyranoside (15) was prepared in two steps and 91percent yield from the corresponding fully acetylated 2-azido-2-deoxylactoxyl bromide 13 and was further modified in four steps to give the benzoylated benzyl 4',6'-O-benzylidene-2-deoxy-2--α-D-lactoside 18 in 78percent overall yield.The benzylidene acetal of the latter was cleaved to give the diol 19 the pyruvation of which as for compound 9 afforded the corresponding pyruvated lactosamine derivative 20 (81percent).Hydrogenolysis of 20 followed by treatment with trichloroacetonitrile gave the corresponding pyruvated disaccharide trichloroacetimidate 22 (77percent).Coupling of the latter with Z-protected 5-amino-1-pentanol followed by deblocking of the intermediates furnished 5-aminopentyl 2-acetamido-4',6'-O--2-deoxy-β-D-lactoside 82).Similarly, condensation of 22 with 5-pentyl 2,4-di-O-benzyl-β-L-fucopyranoside (25) followed by deblocking of the intermediate trisaccharide afforded 5-aminopentyl O--β-D-galactopyranosyl>-(1-->4)-2-acetamido-2-deoxy-β-D-glucopyranoside-(1-->3)-β-L-fucopyranoside (3).Saccharides 2 and 3, represents fragments of the Microciona prolifera aggregation factor. - Key Words: Glycosides, pyruvated/ Sponge, marine/ Microciona prolifera
