ISBN 978-3-8439-1407-9

978-3-8439-1407-9, Reihe Organische Chemie

Andreas Termath
Stereoselektive Totalsynthese von α-Tocopherol durch Cu-katalysierte asymmetrische 1,4-Addition an ein Chromenon

419 Seiten, Dissertation Universität Köln (2013), Softcover, A5

Zusammenfassung / Abstract

This work describes an efficient, highly stereoselective synthesis of (2R)-alpha-Tocopherol, the most prominent member of the Vitamin E family. As a keystep serves a conjugate-addition to an activated chromenone substrate, for which a reliable preparation procedure was developed. The asymmetric Cu-catalyzed 1,4-addition of trimethylaluminium for the generation of the quaternary center (in the presence of a MonoPhos ligand) afforded the product in excellent yield and selectivity. In addition to this, conjugate addition of several Al organyls to related substrates was shown to proceed under Ni-catalysis, most likely via a radical mechanism.