Organic Syntheses by Means of Functionalized Polymer : Cyclization of Polymer-bound Oligo- e -aminocaproic acid Esters

There has been a proposed theory that the polymer-bound cyclization method favors intramolecular reactions over intermolecular reactions due to 'a dilution effect' caused by isolation of a reactions center through binding to a polymer. In order to test this theory, new polymer-bound active esters have been prepared and tendency for intramolecular cyclization of these esters has been investigated. In particular, the intramolecular cyclization of oigo-ε-aminocaproic acid is performed as a model for cyclization of a large peptide. Thus, the N-hydroxy-maleimide esters of oligo-ε-aminocaproic acid protected at the N-terminals have been prepard as new polymerizable active-ester monomers, and polymer-bound active esters have been obtained therefrom through an alternating polymerization in the presence of styrene and a maleimide type comonomer