ISSN:
0170-2041
Schlagwort(e):
Carbohydrates
;
Amphiphilic d-galacturonic acid derivatives
;
Liquid crystals
;
Discotics
;
Calculations, MM2
;
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
D-Galacturonic Acid Derivatives, VI. - D-Galacturonic Acid Derivatives with Liquid Crystalline PropertiesEsters, thioesters, and amides of D-galacturonic acid have been synthesized from alcohols, thioalcohols, and amines having long alkyl chains. Key intermediate of the reaction with the different nucleophiles was the 1,2;3,4-di-O-isopropylidene-α-D-galactopyranuronosyl chloride (3). Deisopropylidenation of the protected esters, thioesters, and amides was achieved by trifluoroacetic acid. The investigation of the liquid crystalline properties was carried out with a polarizing microscop, DSC measurements, and X-ray diffraction. Molecules with three long alkyl chains can be obtained by reaction of amides 5h and 5i with thioalcohols. MM2 calculations voted a Y-shaped structure of the mercaptals 8a and 8b which do exhibit thermotropically a columnar hexagonal mesophase (Dhd) as we have proved by X-ray diffraction.
Zusätzliches Material:
1 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/jlac.1992199201192
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