Cyclohexaamylose derivatives, preparation

In analogy to the derivative prepared by Breslow and Overman, the cyclohexaamylose-iV-methylhydroxamic acid displays a pronounced specificity for p-nitrophenyl acetate as opposed to n-nitrophenyl acetate. This specificity is probably again derived from the geometry of the inclusion complex i.e., a more favorable location of the reactive center of the para-isomer relative to the hydroxamate function within the inclusion complex. 

In an attempt to prepare a catalytically active cycloamylose derivative which would retain the binding properties of an unmodified cycloamylose,7 Gruhn and Bender (1971) attached a relatively small hydroxamate function to a secondary hydroxyl group of cyclohexaamylose. The initial and most important step in the synthetic sequence is the reaction of ionized cyclo-... 

Cyclohexaamylose continued) mono-6-O-tosyl-, preparation of, 23 250 pyridine-2,5-dicarboxylic acid derivative, catalytic action of, 23 251 separation of, by complexing, 23 214 structure, stereochemistry and physical properties of, 23 210-213... 

Melton and Slessor207 have prepared mono-6-chloro-6-deoxy-, mono-6-bromo-6-deoxy-, and mono-6-deoxy-6-iodo-cyclohexaamylose by nucleophilic displacements of the sulfonate group in mono-6-O-p-tolylsulfonylcyclohexaamylose. The monoiodo and monochloro derivatives were each reduced to mono-6-deoxycyclohexaamylose over W-2 and W-4 Raney nickel catalysts, respectively. 

The preparation of monosubstituted cycloamyloses has also been achieved, and depends primarily on the isolation of 6-O-p-tolylsulfonyl-cyclohexaamylose from the products of short-term p-toluenesulfonylation of cyclohexaamylose. By appropriate, nucleophilic displacements, this compound may be converted into the 6-azido-6-deoxy, 6-bromo-6-deoxy, 6-chloro-6-deoxy, and 6-deoxy-6-iodo derivatives reduction of the azide and iodide gives 6-amino-6-deoxy- and 6-deoxy-cyclohexaamylose, respectively. The preparation of monoesters, namely, cyclohexaamylose monobenzoate, cyclohexaamylose 2,5-pyridinedicarboxylate, and... 

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