Artículos de revistas
1,5-asymmetric Induction In Boron-mediated Aldol Reactions Of Beta-oxygenated Methyl Ketones.
Registro en:
Chemical Society Reviews. v. 37, n. 3, p. 451-69, 2008-Mar.
0306-0012
10.1039/b701081h
18224256
Autor
Dias, Luiz C
Aguilar, Andrea M
Institución
Resumen
This tutorial review describes that high levels of substrate-controlled, 1,5-stereoinduction are obtained in the boron-mediated aldol reactions of beta-oxygenated methyl ketones with achiral and chiral aldehydes. Remote induction from the boron enolates gives the 1,5-anti adducts, with the enolate pi-facial selectivity critically dependent upon the nature of the beta-alkoxy protecting group. This 1,5-anti aldol methodology has been strategically employed in the total synthesis of several natural products with remarkable pharmacological activities. At present, the origin of the high level of 1,5-anti induction obtained with the boron enolates is unclear, although a model based on hydrogen bonding between the beta-alkoxy oxygen and the formyl aldehyde hydrogen has recently been proposed. 37 451-69