Alternatively for mipdatabase quick searches go here

Custom Search

Abstract: Imprinted polymers were prepared using a functional monomer derived from boronophthalide and a number of steroid templates bearing spatially separated hydroxyl groups. The cooperative nature of the binding interaction was demonstrated in polymers imprinted with androst-5-ene-3 beta,17 beta-diol and its structural analogues. The stoichiometry and kinetics of binding were probed using LR spectroscopy, selective solvent extractions, and chemical modification experiments. The feasibility of using imprinted polymers as reusable protecting groups was established by the regioselective acylation of trihydroxysteroids bound to polymers imprinted with structurally related diols. In polymers prepared with tert-butyl ester templates ''matched'' to the substrate, regioselectivities as high as 23.1:1 (24-acetate:3-acetate) in the monoester products (65% of recovered material) were seen. In the ''unmarched'' case, the ratio fell to 5.4:1; however, in functionally identical control polymers, imprinted with ethylene glycol, the regioselectivity was completely reversed (< 1:100), and only poor yields of monoesters (13%) were obtained