Amino polyethers

Deoxy-2-[ F]fluoro-D-mannose ( F-2DFM) was prepared through treatment of 201 (see Section 11,2) with F-Bu4NF(MeCN, 75°, 30 min) or K F crown ether, as reported for the cold synthesis. F-2DFM was also prepared from methyl 4,6-di-0-acetyl-3-C>-benzoyl-2-C>-triflyl-a-D-glu-copyranoside with amino(polyether)-supported, carrier-free [ F]fluoride. 

Critical micelle concentration (Section 19 5) Concentration above which substances such as salts of fatty acids aggre gate to form micelles in aqueous solution Crown ether (Section 16 4) A cyclic polyether that via lon-dipole attractive forces forms stable complexes with metal 10ns Such complexes along with their accompany mg anion are soluble in nonpolar solvents C terminus (Section 27 7) The amino acid at the end of a pep tide or protein chain that has its carboxyl group intact—that IS in which the carboxyl group is not part of a peptide bond Cumulated diene (Section 10 5) Diene of the type C=C=C in which a single carbon atom participates in double bonds with two others... 

Other backbone stmctures that have generated a great interest are the polyether ketones. An attempt was made to synthesize amino-terminated arylene ether ketones, which were subsequendy converted into the corresponding maleinhde-terrninated oligomers (26). The aim of this approach was to obtain tough, solvent-resistant, high temperature thermosets. 

Aldehydes Propionates Cyclic polyethers a-Amino acids Hydroperoxides C2H5, CHO... 

PUR are a broad class of highly cross-linked plastics prepared by multiple additions of poly-functional hydroxyl or amino compounds. Typical reactants are polyisocyanates [toluene diisocyanate (TDI)] and polyhydroxyl molecules such as polyols, glycols, polyesters, and polyethers. The cyanate group can also combine with water this reaction is the basis for hardening of the one-part foam formulations. 

Polysaccharide analogue, polyether 15, prepared through anionic cyclopolymerization, was chemically bonded to silica gel.73 The CSP resolved several a-amino acids the chiral recognition abilities of the analogue of 15 have been evaluated.74... 

Chirality derived from the readily accessible a-amino acids has been incorporated into the side chains of aza and diaza macrocyclic polyethers. A number of procedures suitable for peptide synthesis have proved (178) to be unsuitable for acylating the relatively unreactive secondary amine groups of aza crown ethers. Eventually, it was discovered that mixed anhydrides of diphenylphos-phinic acid and alkoxycarbonyl-L-alanine derivatives do yield amides, which can be reduced to the corresponding amines, e.g., l-172. By contrast, the corresponding bisamides of diaza-15-crown-S derivatives could not be reduced and so an alternative approach, involving the use of chiral A-chloroacetamido alcohols derived from a-amino acids, has been employed (178) in the synthesis of chiral receptors, such as ll-173 to ll-175, based on this constitution. 

Santerre and collaborators [72,73] also found that the plasma interaction of polyether urethanes was significantly altered by incorporation of sulfonate groups [73] which could be derivatized with amino adds [72]. The synergistic effect of pendant PEO and sulfonate groups grafted onto polyurethanes resulted in prolonged ex vivo occlusion times [482]. These results corresponded well with... 

Polyether acrylates Polyether acrylates are produced by esterification of polyetherols with acrylic acid. They have a very low viscosity and do not require reactive thinners. Amino-modified polyether acrylates have a higher reactivity and low skin irritance, similar to polyester acrylates. 

Polyfunctional OH Components (Crosslinkers). For crosslinking, trifunctional alcohols are used mainly. Some are of the same type as the difunctional prepolymers—e.g., polyethers derived from trifunctional initiators (glycerol, trimethylolpropane, 1,2,6-hexanetriol) and propylene or butylene oxide—and are preferred. Low molecular weight alcohols are used also. Examples are the ones listed above and glycerol monoricinole-ate, glycerol triricinoleate and amino alcohols like triethanolamine. 

The enniatins and beauveracin are cyclic hexadepsipeptides and so are 18-membered macrocycles built up of alternating amino acid and carboxylic acid residues. They exhibit lower selectivity than (137) and consequently are more broad spectrum ionophores. The structure of (138)KI has been solved544 but it was not possible to conclude, with certainty, whether the metal is entrapped in the central cavity, as in related cyclic polyether structures (Figure 14a), or whether it occupi.es a site between two adjacent ligand molecules to give an infinite sandwich (147) as has been found in the RbNCS complex of a synthetic ldlldl isomer of (138).545 Adducts of 1 2 sandwich and 2 3 club sandwich stoichiometry have been proposed for Cs+ complexes of (138),546a and the 1 2 K+ sandwich complex of (138) has been proposed as the species which transports K+ across lipid layers as it shields the metal effectively from solvent interactions.5461 ... 

A considerable number of NQR studies have been made on zinc and cadmium complexes, for example, the 35C1, 81Br and 127I NQR spectra of a number of CdX2-polyether complexes have been reported and indicate that the compounds are dimeric in solution, with symmetrical halogen bridges between the metal atoms.69 A number of amino acids and peptide complexes of cadmium(II) have been investigated by 14N NQR spectroscopy.70... 

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