A mechanistic study on the Hooker oxidation: synthesis of novel indanecarboxylic acid derivatives from lapachol
| Autor: | Sundarababu Baskaran, Marc Lamshöft, Manohar Puppala, Kenneth O. Eyong, Gabriel N. Folefoc, Michael Spiteller, Ponminor Senthil Kumar |
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| Rok vydání: | 2013 |
| Předmět: |
Models
Molecular Stereochemistry Carboxylic acid Diol Phenazine Indane Benzilic acid Keto acids Biochemistry Mechanistic studies Intramolecular aldol reactions Benzilic acid rearrangement chemistry.chemical_compound Aldol reaction Oxidation One-carbon units Oxidative cleavages Physical and Theoretical Chemistry Condensation reactions Lapachol chemistry.chemical_classification Molecular Structure Carboxylic acids Organic Chemistry Alkyl side chains One-pot reaction Carboxylic acid derivatives chemistry Intramolecular force Indans Reaction intermediates Oxidation-Reduction Naphthoquinones |
| Zdroj: | Org. Biomol. Chem.. 11:459-468 |
| ISSN: | 1477-0539 1477-0520 |
| DOI: | 10.1039/c2ob26737c |
| Popis: | The Hooker oxidation is one of the most intriguing transformations wherein lapachol (1) is readily converted to norlapachol (2) in very good yield. This one-pot reaction involves a very intricate mechanism in which the alkyl side chain of lapachol is shortened by one carbon unit. Previous studies have unequivocally established the involvement of an indane carboxylic acid derivative 3, as a key intermediate (Hooker intermediate), and its simultaneous conversion to norlapachol (2) via the oxidative cleavage of vicinol diol and subsequent intramolecular aldol reaction of the resulting keto acid. However, the formation of the key Hooker intermediate 3 from lapachol (1) remains ambiguous. The present study has thrown some light on the formation of the key intermediate 3 from lapachol (1) via benzilic acid rearrangement of the corresponding labile o-diquinone intermediate 8 derived from lapachol. The involvement of o-diquinone intermediate 8 in the Hooker oxidation has been further established by trapping of this labile intermediate as the corresponding phenazine derivative 9. The involvement of benzilic acid rearrangement as a key step in the Hooker oxidation is further shown with a variety of o-quinones prepared from lapachol (1). � The Royal Society of Chemistry 2013. |
| Databáze: | OpenAIRE |
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