Enantioselektive Totalsynthese von Vitamin E und Entwicklung neuartiger stereoselektiver Domino-Reaktionen (English shop)

Preview

Table of Contents, Datei (230 KB)
Extract, Datei (260 KB)

In the first part of this work, the total synthesis of vitamin E was completed starting from trimethylhydroquinone in an overall yield of 40 % over ten synthetic steps with an excellent enantioselectivity of 98 % with respect to the stereogenic centre at C-2. The key step of this total synthesis is the enantioselective palladium-catalysed domino Wacker–Heck reaction.

In the second part, investigations were carried out on the optimisation of the domino Wacker–Heck reaction with regard to the reaction time and the required amounts of catalyst and chiral ligand by varying the ligand employed.

In the third part of this work, a novel enantioselective domino Wacker–CO insertion process was developed, which allows the conversion of aromatic phenols with various aliphatic and aromatic alcohols into the corresponding esters in good to very good yields and very good enantiomeric excesses. Furthermore, this novel domino reaction enables the construction of differently substituted 2,3-dihydrobenzo[1.4]dioxines in very good yields and very good enantiomeric excesses.