Diastereoselective aldol condensation of directly generated titanium enolates of activated esters.
摘要:
Simply generated (TiCl4, Et3N, -78-degrees-C) titanium enolates of some thioesters and alpha-thio substituted esters undergo aldol condensations with achiral and chiral aldehydes with low to high stereoselectivity. An H-1-NMR study of the TiCl4/ester complexation and of the enolization process is presented. The relation between the enolate structure and the aldol product stereochemistry is discussed.
Diastereoselective aldol condensation of directly generated titanium enolates of activated esters.
摘要:
Simply generated (TiCl4, Et3N, -78-degrees-C) titanium enolates of some thioesters and alpha-thio substituted esters undergo aldol condensations with achiral and chiral aldehydes with low to high stereoselectivity. An H-1-NMR study of the TiCl4/ester complexation and of the enolization process is presented. The relation between the enolate structure and the aldol product stereochemistry is discussed.