Benzo[a]azulenediones and 10,10′‐Bibenzo[a]azulene |
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| Authors: | Rolf Sigrist Hans‐Jürgen Hansen |
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| Affiliation: | 1. Organisch‐chemisches Institut der Universit?t Zürich, Winterthurerstrasse 190, CH‐8057 Zürich, (phone: +41‐44‐6354231;2. fax: +41‐44‐6356833) |
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| Abstract: | The oxidation of benzoa]azulene ( 4 ) with commercial MnO2 in dioxane/H2O leads to a number of products in low yield (Table 1). Treatment of 4 with ‘mild’ MnO2 (MnO2/C) in dioxane/5% H2O results in the formation of 10,10′‐bibenzoa]azulene ( 18 ) in yields of up to 59% of isolated and purified material. Compound 18 exhibits atropisomerism and can be separated by HPLC on a Chiralcel column at room temperature into its stable antipodes (Fig.). |
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| Keywords: | Oxidation Atroposomerism Benzo[a]azulenes 10 10′ ‐Bibenzo[a]azulene |
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