ORGN 396 |
Electrochemical synthesis of chiral orthoquinone monoketals
| Isabelle Fabre, Denis Deffieux, and Stéphane Quideau. Laboratoire de Chimie des Substances Végétales, Université Bordeaux 1, Centre de Recherche en Chimie Moléculaire, Talence, France |
Orthoquinone monoketals generated by oxidative dearomatization of phenolic compounds are very useful synthons in organic synthesis and constitute valuable intermediates in the total synthesis of numerous natural products. Introduction of a stereogenic carbon center in the ketal cycle can be exploited to control stereochemical outcomes of subsequent reactions at the cyclohexa-2-4-dienone unit. In order to validate this new methodology, access to chiral orthoquinone monoketals of type 1 has been envisaged by electrochemical oxidation. This oxidative method offers an environmentally benign alternative route to the preparation of orthoquinone ketals that are otherwise made by using stoechiometric chemical oxidizing agents such as hypervalent iodine(III) or toxic metal-based reagents. Anodic oxidation of several adequately substituted phenols (e.g., 2) or phenol ethers (e.g., 3) leading to diastereomerically enriched orthoquinone monoketals will be discussed. |
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Physical Organic, Materials, Heterocycles, Aromatics, Metal-Mediated Reactions
8:00 PM-10:00 PM, Tuesday, September 9, 2003 Hilton New York -- Americas Hall 1, Poster
Division of Organic Chemistry
The 226th ACS National Meeting, New York, NY, September 7-11, 2003
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