Tetrahydrofurane und Lactone,I. Synthese und Reaktionen chiraler 2,5-überbrückter Tetrahydrofurane – ein neuer Weg zu optisch aktiven γ-Lactonen und γ-Bislactonen |
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| Authors: | Werner Tochtermann Gunter-Rudolf Schröder Günther Snatzke Eva-maria Peters Karl Peters Hans Georg von Schnering |
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| Institution: | 1. Institut für Organische Chemie der Universität Kiel Olshausenstraße 40, D-2300 Kiel 1;2. Lehrstuhl für Strukturchemie der Universität Bochum, Universitätsstraße 150, D-4630 Bochum 1;3. Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-7000 Stuttgart 80 |
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| Abstract: | Tetrahydrofurans and Lactones, I. - Synthesis and Reactions of Chiral 2,5-Bridged Tetrahydrofurans - A New Approach to Optically Active γ-Lactones and γ-Bislactones Diels-Alder reaction of 3,4-hexamethylenefuran with acrylic acid gives the carboxylic acid 1a with high endo selectivity. 1a was separated into the enantiomers via the α-phenylethylammonium salts. Comparison of the CD spectra of (?)- 1a and (?)- 3 and the X-ray structural analysis of the camphanoyl derivative (?)- 4b lead to the 1R,2S,4S configuration of (?)- 1a as well. The 2,5-bridged tetrahydrofuran (?)- 5 with all-cis and RSS configuration is obtained by ozonolysis of the ester (?)- 1b . (?)- 5 can be oxidized to the γ-lactone (2R,3S)-(?)- 6 with sodium metaperiodate/potassium permanganate in 22% yield. Hydride reduction of (?)- 6 under various conditions leads to the γ-bislactones (?)- 8 and (?)- 9 or to the bislactol (?)- 10 . (?)- 8 has the same absolute configuration as the naturally occuring (?)-canadensolide. |
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