Stereoselective additions to carboxylic acid dianions and β-lactone substituted ester enolates
作者:Johann Mulzer、Peter De Lasalle、Alexander Chucholowski、Ursula Blaschek、Gisela Brüntrup、Ibrahim Jibril、Gottfried Huttner
DOI:10.1016/0040-4020(84)80003-4
日期:1984.1
β-unsaturated β-hydroxy-carboxylic acids 2a/b. A diastereo- and enantioselective aldoltype addition of phenylacetic acid dianion to benzaldehyde has been achieved by employing optically active alkoxide amide bases. Finally, highly stereocontrolled additions to the novel β-lactone substituted ester enolates 22 are described.
The titanium tetrachloride catalyzed condensation of the title acetals with aldehydes, leads to threo or erythro β-hydroxyacids with good stereoselectivity which depends mainly on the nature of the acetal counterion.