Jozef Hodyl PhD Thesis - Theses - Flinders University

The chiral phenolic epoxide 56 was prepared by an established method, firstformulated by Klunder, 168, 169 and subsequently modified by Smith, 94 in 74% yieldfrom the reaction of phenol, 57, with enantiomerically pure (2S)-(+)-glycidyltosylate, 58, Scheme 2.5. 1 H NMR and 13 C NMR spectral data agreed with literaturevalues. 945758 56Scheme 2.5 Synthesis of chiral phenolic epoxide 56.2.4.1 Preparation of hydroxy terminated polyether (HTPE) appended pendantarm epoxides with enhanced hydrophilicityTo impart and improve wettability in aqueous solution to the silica immobilisedmacrocyclic receptor materials, functional groups that increase their hydrophiliccharacter seemed appropriate. Reasoning that the elements of the receptorsdisplaying most contact with the ambient solution are the upwardly projectingpendant arms, it was determined that, modification of these pendant arms to augmenttheir contact with the aqueous environment and, confer hydrophilicity at theperiphery of the receptors would satisfy the objective for increased receptorwettability in aqueous solution.The choice of adding a “dendritic” hydroxy terminated polyether chain to eachpendant arm developed from other studies pursuing the same objective of instillinghydrophilic properties to their synthetic targets. 170-173 Synthesis of the pendant armHTPE epoxides 59 and 60 does not reflect the ease of producing phenolic epoxide,56, and requires a four step process as shown in Scheme 2.6.43