ChemInform Abstract: Amphiphilic and Mesogenic Carbohydrates. Part 2. Synthesis and Characterization of Mono‐O‐(n‐alkyl)‐D‐glucose Derivatives.

Abstract

Amphiphilic and Mesogenic Carbohydrates. Part 2. Synthesis and Characterization of Mono-O-(n-alkyl)-D-glucose Derivatives. -Title compounds of type (III) and (V), (VII) (prepared similarly) form a mesogenic phase. Molecules (III) show great differences between melting and clear points. -(MIETHCHEN, R.; HOLZ, J.; PRADE, H.; LIPTAK, A.; Tetrahedron 48 (1992) 15, 3061-3068; Dep. Org. Chem., Univ. Rostock, O-2500 Rostock, Fed. Rep. Ger.; EN)

New insights into the transitional behaviour of methyl-6-O-(n-dodecanoyl)-α-D-glucopyranoside using variable temperature FTIR spectroscopy and X-ray diffraction

“…This view is consistent with both the spectroscopic changes observed in the ν~1470 cm −1 region, see Figure 11, and with the interdigitated smectic arrangement found using X-ray diffraction, see Figure 5. It is also noteworthy that the corresponding materials but without the carbonyl link, the methyl-6-O-(n-alkyl)-α-D-glucopyranosides, do not exhibit liquid crystallinity [10], providing further evidence that the carbonyl groups participate in the hydrogen bonding required for smectic phase stabilisation. From a general molecular design viewpoint, this observation highlights the key role of the linker group between the polar head and the hydrophobic chains in promoting thermotropic liquid crystallinity in this class of sugar-based mesogens.…”

“…[2] Carbohydrate-based liquid crystals can also exhibit thermotropic mesophases. [8][9][10] Their exciting application potential includes their use as hydrogels or electrolytes whose physical properties can be tuned by external stimuli such as UV light or mechanical forces. [11][12][13][14][15] It is clear that the successful design of new liquid crystal carbohydrates now requires an improved understanding of the empirical relationships between molecular structure and aggregation behaviour.…”

Catalytic reductive cleavage of methyl α-d-glucoside acetals to ethers using hydrogen as a clean reductant

“…All other reagents and solvents were used as received without further purification. NMR spectra were acquired on a Bruker 300 ( 1 H, 300 MHz; 13 C, 75 MHz) spectrometer at 293 K. Electrospray ionization (ESI) mass spectra (MS) and High-Resolution Mass Spectra (HRMS) were recorded in the positive mode using spectrometer (MicroTOFQ-II, Bruker Daltonics, Bremen). Thin-layer chromatography (TLC) was carried out on aluminum sheets coated with silica gel Merck 60 F254 (0.25 mm) revealed with a solution of sulfuric acid at 2.5 v/v% in ethanol.…”

“…In order to install the ether functionality, traditional methods usually rely on the Williamson synthesis using a strong base and an alkyl halide or pseudo-halide. 13 For obvious selectivity reasons, this protocol requires multi-step protection/deprotection strategies, resulting in a low atomeconomy and the production of large quantities of waste. When carrying out using prior protections, the reaction affords low selectivity and moderate yields.…”