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The asymmetric Robinson cyclization reaction was studied by using polymer-bound L-prolines as catalysts, in which the degree of crosslinking, the content of proline and the spacers of binding L-proline to the polymers were varied. Incorporation of a spacer for binding the L-proline moiety onto a polymer support was found to improve the catalytic efficiency considerably, which is reflected by the value of enantiomeric excess.

Chitosan is a polysaccharide consisting predominantly of unbranched chains of /l-( 1,4)-2-. amino-2-deoxy-D-glucose residues. It can be readily obtained by hydrolysis from chitin, which exists naturally in fungi and arthropods. Recently, the effective use of chitin and chitosan'), and their congeners2-4, for inorganic chromatography has been demonstrated, as they can act as excellent chelating agents. It was also found that the adsorption ability of chitosan is generally much higher than that of chitin. However, chitosan is known to be poor in mechanical properties in water, and the presence of free amino groups enhances its solubility, particularly in acidic media.

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