Amylose benzoate

FIGURE 3 The chemical structures of cellulose benzoate, amylose benzoate, and carbamate derivatives. (From Ref. 32.)... 

Physicochemical studies of the solution properties of amylose benzoate by light-scattering, osmometric, and viscosimetric techniques showed that the molecules behave as coils. Factors affecting the rate of dissolution of cellulose acetate phthalate in aqueous solution are important from the point of view of use as an enteric-coating material. The removal of the benzoyl group during methanolysis is slow and concurrent with the methanolysis, " whereas deacetylation precedes methanolysis. 

Amylose benzoate Fractional solution Nitromethane/methanol 31°C 2525,2526,2527... 

Amylene, stabilizer for solvents 120 Amylose reagent 173 a-Amyrin 44,69 jS-Amyrin 69 a-Amyrin benzoate 63 Anabolics 303, 411, 430,432 Anacardol 288... 

The most useful CSPs for the resolution of many varied, structurally different racemates are the following the peracetates, benzoates (and derivatives) and carbamates (and derivatives) of cellulose and amylose coated on wide pore silica gel. Some of these polymer derivatives are also potentially useful as pure polymeric bead material, but mainly for preparative purposes. 

Expansion of these investigations to other types of polysaccharide derivatives led to the development of silica-coated versions of cellulose and amylose carbamates and benzoates [100-102]. These CSPs showed particularly versatile chiral recognition profiles, resolving an extremely broad assortment of chiral analytes. Several of these CSPs have been commercialized by Daicel Chemical Industries, Ltd., the most important ofwhich are depicted in Fig. 7.5. 

SMB parameters Cellulose tris(p-methyl- benzoate) beads Poly(N-acryloyl-amino acid ester) silica CSP Cellulose tris(p-methylbenzoate) coated on silica (Chiralcel OJ) Amylose tris(3,5-dimethylphenyl-carbamate) coated on silica (Chiralpak AD)... 

The direction of sodium benzoate and benzoic acid penetration of the cyclohexa-amylose cavity in aqueous solution has been determined by n.m.r. spectroscopy of the respective cycloamylose complexes. Results suggested that benzoic acid has a strong preference for binding in the cycloamylose cavity, while sodium benzoate binding is more random. Both compounds form 1 1 complexes with cyclohexa-amylose. 

Heptakis-(2-0-methyl)cyclohepta-amylose has been prepared by methylation of heptakis-(6-bromo-6-deoxy)cyclohepta-amylose and regeneration of the primary hydroxy-groups in the resulting heptakis-(6-bromo-6-deoxy-2-0-methyl)-cyclohepta-amylose by benzoate exchange and debenzoylation. The O-methyl groups in tetradeca-O-methylcyclohepta-amylose are located at 0-2 and 0-6 of the hexose residues. 

Ch nevert, R. and Voyer, N., Photochemical rearrangement of phenyl benzoate in the presence of cyclodextrins and amylose. Tetrahedron Lett., 25, 5007, 1984. 

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