A Strategy of “Random Glycosylation” for the Production of Oligosaccharide Libraries

Abstract

Amidea 1 wcrr \ynthesired by thc reaction sequence: Br(CH,).COCI + Br(CH,),,CONHPhNO, -+ [C,,H,,N+(CH,),(CH,),CONHPhNO~] Br-. After recr)stalIiratioii from EtOAcCH,CN l a had a melting point of 208-209 "C and I b melted at 156-1.57 C . Gitionic substrate 2 was obtained as a gel-like, yellow solid from N-methyl-/~-nitroaniline according to the Scheme for 1 above. All compounds had ' H and "C NMR spectra and elemental analysis consistent with given formulae. Kinetic data were obtained by following the absorbance of reaction mixtures containing surfactant components at 390 nm (Table 1). All UViVis data were obtained with a Hewlett-Packard Model 8450 spectrophotometer. Mixture components were added to the cuvet by pipet and shaken vigorously by hand for 2-3 s.The results were not influenced by the order of addition of mixture components.

Oligosaccharide Synthesis on Solid, Soluble Polymer, and Tag Supports

“…Random glycosylation strategy is a promising method for obtaining a certain oligosaccharide library in a single procedure. According to the pioneering Hindsgaul protocol, 21 glycosylated "randomly" with the appropriate donors, such as fucosyl trichloroacetimide, to give glycoside isomers with all possible anomeric configurations and linkage positions. This random strategy was also applied to the solid-supported synthesis by Thiem and coworkers (Scheme 16.12).…”

Combinatorial Synthesis of an Oligosaccharide Library by Using β‐Bromoglycoside‐Mediated Iterative Glycosylation of Selenoglycosides: Rapid Expansion of Molecular Diversity with Simple Building Blocks

“…While random glycosylation has been reported to increase such structural diversity. [18] The resulting library comprises an inseparable mixture of regio-and stereoisomers. However, the iterative glycosylation approach would generate libraries composed of structurally defined oligosaccharides.…”

Lipase‐Catalysed Regioselective Acylations in Combination with Regioselective Glycosylations as a Strategy for the Synthesis of Oligosaccharides: Synthesis of a Series of Fucosyllactose Building Blocks

“…[5] In order to establish whether the antiadhesion properties of these compounds are merely due to the presence of fucose or whether glycosylation position plays a role in determining the bioactivity, we planned to synthesise a series of regioisomeric fucosyllactoses illustrated in Figure 1. [6] The synthesis of this small trisaccharide library could be approached in different ways: (i) the classical target-oriented synthesis, consisting of the independent systematic preparation of each member of the family, would give the best results in terms of yield but would be very laborious [a] and time consuming; (ii) the building-block approach, employed in many syntheses, [7] relies on orthogonally protected acceptor precursors, which require the selective deprotection of each single hydroxyl group followed by its glycosylation; (iii) the ''random glycosylation'' concept proposed by Hindsgaul [8] (one unprotected acceptor and one donor) produces mixtures of all the possible regioisomeric oligosaccharides. However, the latter is only very convenient if one is interested in testing the mixture itself in a biological assay.…”

“…8 Hz, 1 H, CHHPh), 7.27Ϫ7.45 (m, 10 H, 2 C 6 H 5 ) ppm. 13 C NMR, (100.62 MHz, CDCl 3 ): δ ϭ 15.7 (6c-C), 61.0 (6a-C), 66.6 (5c-C), 67.4 (6b-C), 69.2 (4b-C), 69.7 (3c-C), 70.8 (CH 2 Ph), 71.4 (2b-C), 72.8 (2c-C), 72.9 (CH 2 Ph), 73.8 (4c-C), 73.9 (2a-C, 3b-C), 75.3 (3a-C), 75.5 (5a-C), 76.7 (5b-C), 79.9 (4a-C), 98.4 (1c-C); 102.1 (1b-C), 104.…”