Thesis-Final 03 June 2011 pdf - Jacobs University

Conclusions Chapter 4
Conclusions
A series of mono-acyl chlorogenic acids, in particular substituted in the 1-, 3, -4- and
5- position of the quinic acid with coumaroyl, feruloyl, caffeoyl and dimethoxy
cinnamoyl substituents have been successfully synthesized. The improvement of the
existing Sefkow’s acylation method allowed for some of the first synthesis of
chlorogenic acids to be established. As intermediates in these synthesis 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 and poly-acyl chlorogenic acids have been successfully synthesized. A general
protection and deprotection strategy for the synthesis of chlorogenic acids has been
established. The list of the synthesised compounds in this thesis and applied methods
for each type of the synthesis in general is mentioned in the following paragraphs.
During the experimental work it was observed that chlorogenic acids are sensitive to
air and less stable than ester forms. Keeping in mind that the reference materials
should be available for future work of the project, chain opening reactions in THF/
H 2 O solution wasn’t performed for every product.
Acid chlorides
The method for synthesis of acid chlorides di-acetyl caffeic acid chloride, acetyl
ferulic acid chloride, acetyl p-coumaric acid chloride was available in the literature.
Cinnamoyl chloride is the only commercially available acyl chloride, which was used
for synthesis. The 3, 4-dimethoxycinnamic acid chloride (44) is a new type of acyl
chloride which is also prepared for the synthesis. The list of the acyl chlorides which
were synthesised is shown below;
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