Revisiting the armed-disarmed concept rationale: s-benzoxazolyl glycosides in chemoselective oligosaccharide synthesis.

[reaction: see text]. It has been discovered that 2-O-benzyl-3,4,6-tri-O-acyl SBox glycosides are significantly less reactive than even "disarmed" peracylated derivatives. This finding has been applied to the synthesis of various oligosaccharides, the monomeric units of which are connected via cis-cis, trans-cis, and cis-trans sequential glycosidic linkages. Two-stage activation of the armed (benzylated) donor over moderately (dis)armed (acylated) and, subsequently, over disarmed (2-O-benzyl-3,4-O-diacylated) acceptor has also proven to be feasible.

[1]  M. Kamat,et al.  Remote Participation‐Assisted Synthesis of β‐Mannosides , 2005 .

[2]  A. Demchenko,et al.  Potent, versatile, and stable: thiazolyl thioglycosides as glycosyl donors. , 2004, Angewandte Chemie.

[3]  M. Kamat,et al.  S-Benzoxazolyl (SBox) Glycosides in Oligosaccharide Synthesis: Novel Glycosylation Approach to the Synthesis of β-d-Glucosides, β-d-Galactosides, and α-d-Mannosides , 2003 .

[4]  A. Demchenko,et al.  S-Benzoxazolyl (SBox) glycosides as novel, versatile glycosyl donors for stereoselective 1,2-cis glycosylation. , 2003, Organic letters.

[5]  G. Boons.  Strategies in Oligosaccharide Synthesis , 1996 .

[6]  A. Varki,et al.  Biological roles of oligosaccharides: all of the theories are correct , 1993, Glycobiology.

[7]  R. Madsen,et al.  n-Pentenyl Glycosides in Organic Chemistry: A Contemporary Example of Serendipity , 1992 .

[8]  H. Ottosson,et al.  Armed/disarmed effects in glycosyl donors: rationalization and sidetracking , 1990 .

[9]  J. H. Boom,et al.  An efficient thioglycoside-mediated formation of α-glycosidic linkages promoted by iodonium dicollidine perchlorate , 1990 .

[10]  P. Konradsson,et al.  Armed and disarmed n-pentenyl glycosides in saccharide couplings leading to oligosaccharides , 1988 .

[11]  P. Konradsson,et al.  Direct elaboration of pent-4-enyl glycosides into disaccharides , 1988 .

[12]  H. Paulsen.  Advances in Selective Chemical Syntheses of Complex Oligosaccharides , 1982 .

[13]  I. Dyong,et al.  Partiell benzylierte Kohlenhydrate, 2. Synthese aller Methyl‐mono‐, Methyl‐di‐ und Methyl‐tri‐O‐benzyl‐α‐D‐glucopyranoside. , 1975 .

[14]  A. F. Bochkov,et al.  A new method of glycosylation , 1967 .

[15]  R. Lemieux.  Some implications in carbohydrate chemistry of theories relating to the mechanisms of replacement reactions. , 1954, Advances in carbohydrate chemistry.