Enantioselective synthesis and olfactory evaluation of 13-alkyl-substituted alpha-ionones.
Chem Biodivers
; 5(6): 1045-57, 2008 Jun.
Article
em En
| MEDLINE
| ID: mdl-18618393
ABSTRACT
To study the influence of the steric bulk of the substituents at C(5) on the olfactory characteristics of alpha-ionone, the (S)-antipodes of compounds 8-10 were synthesized starting from (S)-alpha-cyclogeraniol (14a). The latter was available in useful preparative yield with 95% ee by enantioselective lipase-PS-mediated acetylation of the racemic mixture. Key step in the conversion of 14a to 8-10 was an S(N)2'-type reaction of an organocuprate on the allylic phosphate 20, which appears to be a general method for the introduction of an alkyl substituent at the cyclohexene C=C bond of ionones. Olfactory evaluation showed that, compared to the parent (S)-alpha-ionone (1), the odor strength and fragrance facets of the three analogues 8-10 are significantly influenced by the bulkiness of the substituent at C(13), giving further evidence that hydrophobic interactions of this group play a significant role in the chemoreception of ionones. In particular, the odor of the ethyl derivative 8 was found to be significantly stronger than that of the parent (S)-alpha-ionone (1).
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Perfumes
/
Norisoprenoides
/
Odorantes
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article