Asymmetric hydrogenation of 3-methyl-fumaric and maleic ester monoaldehydes protected as neph-derived oxazolidines
摘要:
The hydrogenation of 3-methyl-fumaric and maleic ester mono aldehydes protected as oxazolidines of nor-ephedrine (NEPH) derivation has been studied. This transformation takes place with moderate to good pi-face stereodifferentiation and allows the preparation of non-racemic 3-methyl-succinaldehydic acid methyl ester (1, R = Me). The factors dictating the diastereocontrol are discussed.
A new procedure for Horner-Wadsworth-Emmons olefination of carbonyl compounds
作者:Francesco Bonadies、Antonella Cardilli、Alessandra Lattanzi、Liliana R. Orelli、Arrigo Scettri
DOI:10.1016/s0040-4039(00)76914-0
日期:1994.5
aldehydes undergo an efficient E-stereoselective Horner-Wadsworth-Emmonsolefination by generation of phosphonate carbanion with lithium hydroxide. The reaction proceeds satisfactorily with linear, cyclic, polifunctional ketones in the presence of activated zeolites and and by the slow addition of the base.