Gd(OTf)3-catalyzed synthesis of geranyl esters for the intramolecular radical cyclization of their epoxides mediated by titanocene (III)
A selective and mild method for the esterification of a variety of carboxylic acids with geraniol is developed. We demonstrated that the use of triphenylphosphine, I2, 2-methylimidazole or imidazole and a catalytic amount of Gd(OTf)3 resulted to be more active than the previous protocols, providing...
- Autores:
- Tipo de recurso:
- Fecha de publicación:
- 2015
- Institución:
- Ministerio de Ciencia, Tecnología e Innovación
- Repositorio:
- Repositorio Minciencias
- Idioma:
- eng
- OAI Identifier:
- oai:repositorio.minciencias.gov.co:20.500.14143/34176
- Acceso en línea:
- http://repositorio.colciencias.gov.co/handle/11146/34176
- Palabra clave:
- Biología vegetal
Biología vegetal
Aceites esenciales
Catalizadores
Tecnología química
Aceites combustibles
Biología vegetal
Biotecnología
- Rights
- License
- http://purl.org/coar/access_right/c_f1cf
| Summary: | A selective and mild method for the esterification of a variety of carboxylic acids with geraniol is developed. We demonstrated that the use of triphenylphosphine, I2, 2-methylimidazole or imidazole and a catalytic amount of Gd(OTf)3 resulted to be more active than the previous protocols, providing a 16-membered library of geranyl esters in higher yields and in shorter reaction times. The use of essential oil of palmarosa (Cymbopogon martinii), enriched with geraniol, as a raw material for the synthesis of the target compounds complemented and proved how sustainable and eco-friendly this protocol is. Finally, the selective 6,7-epoxidation of the obtained geranyl esters led us to study their regio-controlled radical cyclization mediated by titanocene(III) for the synthesis of novel (8-hydroxy-9,9-dimethyl-5-methylene cyclohexyl)methyl esters in moderate yields and with excellent stereoselectivities. |
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