| Título: | SN2' alkylation of chiral allylic cyanohydrin o-phosphates with organocuprates |
| Autores: |
Baeza Carratalá, Alejandro Nájera Domingo, Carmen Sansano Gil, José Miguel |
| Fecha: |
2007-11-02 2007-11-02 2007-01-08 |
| Publicador: | RUA Docencia |
| Fuente: |
 |
| Tipo: | info:eu-repo/semantics/article |
| Tema: |
Cyanohydrins Organocuprates Copper Allylic substitution Asymmetric synthesis Unsaturated nitriles Cyanophosphates Química Orgánica |
| Descripción: |
Enantiomerically enriched cyanohydrin O-phosphates, prepared
by enantioselective cyanophosphorylation of α,β-unsaturated
aldehydes, react regioselectively at the γ-position
with organocuprates derived from alkyl Grignard reagents
and CuCN to afford chiral γ-alkyl-substituted α,β-unsaturated
nitriles. The configuration of the new C–C double bond
is mainly (E) when the reaction is performed at –78 °C and
(Z) when it is carried out at higher temperatures (0 °C). A
high level of transfer of the chirality in the new stereocentre,
corresponding to a stereospecific anti attack onto the cyanophosphate, is observed. Enantiomerically enriched (E)-γ-alkylated
α,β-unsaturated esters are prepared after subsequent
methanolysis in a three-step sequence from the corresponding
α,β-unsaturated aldehydes. In addition, the synthesis of
(R)-4-methylnonan-1-ol, also known as the sex pheromone of
the yellow mealworm Tenebrio molitor L, and its (S) enantiomer
have been carried out in a four-step route from (E)-oct-2-enal. This work has been supported by the DGES of the Spanish Ministerio de Educación y Ciencia (MEC) (CTQ2004-00808/BQU), the Generalitat Valenciana (CTIOIB/2002/320, GRUPOS03/134 and GV05/144) and the University of Alicante. |
| Idioma: | Inglés |
1 Choosing the correct paradigm for unknown words in rule-based machine translation systems por Sánchez Cartagena, Víctor Manuel,Esplà Gomis, Miquel,Sánchez Martínez, Felipe,Pérez Ortiz, Juan Antonio | 6 Análisis Real de Varias Variables II. Problemas (27-3-2013) por Conde Calero, Juan Manuel |
2 Using external sources of bilingual information for on-the-fly word alignment por Esplà Gomis, Miquel,Sánchez Martínez, Felipe,Forcada Zubizarreta, Mikel L. | 7 Introducción a mirada/s trans/identitarias,Introduction to trans-identitary look(s) por Amaro Quintas, Ángel Manuel |
3 | 8 |
4 | 9 |
5 Los espacios periurbanos en el área ibérica contestana: las novedades y algunas reflexiones históricas por Sala Sellés, Feliciana | 10 Matrimonio igualitario y parentesco: discursos, hegemonías y acontecimiento,Egalitarian marriage and kinship: discourses, hegemony and event por Buzaglo, Analía,Morandi, Mariela,Culla, Mónica |