Birgul Surucu

• The chlorogenic acids are a family of esters formed between certain trans-cinnamic acids and quinic acid. Chlorogenic acids are among the most abundant polyphenols, which are naturally occurring in plants, with various biological activities beneficial to human health. Chlorogenic acids are secondary metabolites that are found in plants. As a group they generally contain several subgroups and usually several isomers within each subgroup. The development of methods for the synthesis of existing chlorogenic acids and new series of chlorogenic acids were developed in this thesis in order to have the compounds available as analytical standards, for confirmation of previous and future LC/MS work, and most importantly for individual biological testing in various assays. The target compounds were obtained with two strategies 1.selective synthesis using appropriate protecting groups strategies, 2.nonnselective synthesis producing mixtures of isomers. The general strategy, which was applied through out the thesis in order to synthesise the target compounds was, as follows; - Preperation of acid chlorides of cinnamic acids - Preparation of protected quinic acid derivatives - Acylation - Deprotection A series of mono-acyl chlorogenic acids and esters, in particular of those substituted in the 1-, 3-, 4- and 5- positions of the quinic acid with coumaroyl, feruloyl, caffeoyl and dimethoxy cinnamoyl and cinnamoyl substituents, have been successfully synthesised. As intermediates in these syntheses a series of quinide esters, potential metabolites and degradation products of naturally occurring chlorogenic acids have also been obtained. The first examples of di-acyl chlorogenic acids, have been successfully synthesised. A general protection and deprotection strategy for the synthesis of chlorogenic acids has been established. Poly-acyl chlorogenic acids starting from qunic acid and quinic acid lactones also have been established. The right conditions for the synthesis of certain type of chlorogenic acids and esters have been established in this work.