Original scientific paper

Chiral Chromenes: Synthesis, Separation of Enantiomers and Barriers to Racemization

Linda Lončar ; Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, 41000 Zagreb, Croatia
Klaudio Otočan ; Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, 41000 Zagreb, Croatia
Mladen Mintas ; Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, 41000 Zagreb, Croatia
Thomas Trötsch ; Institut für Organische Chemie, Universitàt Regensburg, 84000 Regensburg, Bundesrepublik Deutschland
Albrecht Mannschreck ; Institut für Organische Chemie, Universitàt Regensburg, 84000 Regensburg, Bundesrepublik Deutschland

Abstract

2ff-Chromenes 3 and 4 have been synthesized by reduction of the appropriate lactone with diisobutylaluminium hydride and subsequent O-alkyla- tion of the resulting lactols. Separations or enrichments of enantiomers were achieved by liquid chromatography on triacetylcellulose and tribenzoylcel- lulose, ( + )-3 and (—)—3 being separated almost completely, while an enrichment of the enantiomers of 4 was achieved by using the recycling procedure. The barriers for the interconversion of enantiomers of 3 and 4 were determined by thermal racemization of enantiomers.

Keywords

Hrčak ID:

137108

URI

https://hrcak.srce.hr/137108

Publication date:

1.6.1993.

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