Your browser doesn't support javascript.
loading
Straightforward asymmetric entry to highly functionalized 3-substituted 3-hydroxy-beta-lactams via Baylis-Hillman or bromoallylation reactions.
Alcaide, Benito; Almendros, Pedro; Aragoncillo, Cristina; Rodríguez-Acebes, Raquel.
Afiliação
  • Alcaide B; Departamento de Química Orgánica I, Facultad de Química, Universidad Complutense de Madrid, 28040-Madrid, Spain. alcaideb@quim.ucm.es
J Org Chem ; 69(3): 826-31, 2004 Feb 06.
Article em En | MEDLINE | ID: mdl-14750811
The reaction of various activated vinyl systems, including 2-cyclopenten-1-one, with enantiopure azetidine-2,3-diones 1 was promoted by DABCO to afford the corresponding optically pure Baylis-Hillman adducts 2 without detectable epimerization. However, the reaction of alpha-keto lactams 1 with but-3-yn-2-one was not as successful, giving the corresponding beta-halo Baylis-Hillman adduct in low yield. Metal-mediated bromoallylation reaction between 2,3-dibromopropene and azetidine-2,3-diones 1 was investigated in aqueous media. Surprisingly, indium was unable to promote the bromoallylation reaction of alpha-keto lactams 1, but the Sn-Hf(4)Cl-promoted bromoallylation of ketones 1 proceeded efficiently to achieve bromohomoallyl alcohols 5 as single diastereomers. On this basis, simple and fast protocols for the asymmetric synthesis of the potentially bioactive 3-substituted 3-hydroxy-beta-lactam moiety were developed.
Assuntos
Buscar no Google
Base de dados: MEDLINE Assunto principal: Azetidinas / Beta-Lactamas / Compostos Alílicos / Hidrocarbonetos Bromados Idioma: En Ano de publicação: 2004 Tipo de documento: Article
Buscar no Google
Base de dados: MEDLINE Assunto principal: Azetidinas / Beta-Lactamas / Compostos Alílicos / Hidrocarbonetos Bromados Idioma: En Ano de publicação: 2004 Tipo de documento: Article