Syntheses of macrocylic enzyme models. Part I. Preparation and properties of [20]paracyclophanes

Abstract

A series of [20]paracyclophane derivatives bearing a functional group or groups on the polymethylene bridge has been prepared, because of their novel enzyme-like functions in acyl-transfer reactions. An electrophilic substitution which introduces a carboxy-group into the benzene ring has been successfully used to afford a bifunctional paracyclophane. All the paracyclophanes have been characterised by ¹H and ¹³C n.m.r. spectroscopy and by i.r. measurements. The major isomer of 11-amino[20]paracyclophan-10-ol(3),2-aminocyclodecanol (13), and [20]paracyclophane-10,11-diol is in each case the threo-isomer, with synperiplanar conformation, as a result of energy gain due to intramolecular hydrogen bonding. The tendency towards hydrogen bonding is more pronounced for the hydrochloride forms of (3) and (13).