Preparation of S-glycoside surfactants and cysteine thioglycosides using minimally competent Lewis acid catalysis
作者:Lajos Z. Szabó、Dillon J. Hanrahan、Evan M. Jones、Erin Martin、Jeanne E. Pemberton、Robin Polt
DOI:10.1016/j.carres.2015.12.008
日期:2016.3
Here we report a method for the preparation of anomerically pure beta-S-glycopyranosides (1,2-trans-glycosides) from the corresponding peracetate donors. S-glycosylation was performed in CHCl3 at reflux in the presence of a catalytic amount of InBr3. Deacylation of the intermediate peracetates were achieved under Zemplen conditions. Five pyranose examples, monosaccharides D-glucose and D-galactose
Thermotropic and lyotropic properties of long chain alkyl glycopyranosides. Part II. Disaccharide headgroups
作者:H.M von Minden、K Brandenburg、U Seydel、M.H.J Koch、V Garamus、R Willumeit、V Vill
DOI:10.1016/s0009-3084(00)00151-1
日期:2000.8
We have investigated the thermotropic and lyotropic properties of some long chain alkyl glycosides with disaccharide headgroups. The thermotropism was measured with polarising microscopy and additionally the lyotropism with the contact preparation method, Fourier-transform Infrared (FTIR) spectroscopy, X-ray diffraction and small angle neutron scattering. A broad thermotropic as well as lyotropic polymorphism was found. The compounds displayed thermotropic S-A (lamellar) and cubic phases, and the investigation of the lyotropic phase behaviour led to the observation of inverted bicontinuous cubic V-II phases, lamellar L-alpha phases, normal bicontinuous cubic V-I phases, normal columnar H-I phases, normal discontinuous cubic I-I f phases and lyotropic cholesteric phases. The phases are discussed with respect to the chemical structures that have been varied systematically to derive structure-property relationships. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.
Highly β-Selective Glycosylation Reactions for the Synthesis of ω-Functionalized Alkyl β-Maltoside as a Co-crystallizing Detergent
作者:M. A. Hossain、S. M. A. Hakim Siddiki、M. Elias、M. M. Rahman、M. A. R. Jamil
DOI:10.1134/s1070428020100231
日期:2020.10
Methods have been reported for the preparation of ω-functionalized alkyl maltoside and glycoside detergents via a simple and inexpensive synthetic route. The key step was stannic chloride-mediated glycosylation of long-chain alcohols or thiols with maltoseoctaacetate at 0 or –10°C, respectively, within a very short time (isolated yield 17–44%), which provided more than 98% β-selectivity.