Titanium and Boron Mediated Aldol Reactions of .beta.-Hydroxy Ketones
摘要:
The reaction of enolates derived from titanium and boron complexes of beta-hydroxy ketones with aldehydes afforded aldol products in good to excellent yields. Whereas the boron mediated reactions gave exclusively anti aldol products derived from the reaction at C-alpha, the titanium mediated reactions produced primarily syn aldol products from reaction at C-alpha. The product selectivities observed in the titanium mediated aldol reactions were highly dependent on the substitution pattern of the starting beta-hydroxy ketone.
these challenges rationally in the case of the enzymatic synthesis of methyl 3‐hydroxy‐2‐methylpropanoate (commonly denoted as the Roche ester) and derivatives thereof using the ene reductase YqjM. By a highly efficient, concept‐based approach of designing mutant variants of YqjM and engineering substrates we could alter both the rate constant and the enantioselectivity of the reaction. Preparative scale
Titanium and Boron Mediated Aldol Reactions of .beta.-Hydroxy Ketones
作者:George P. Luke、Joel Morris
DOI:10.1021/jo00115a015
日期:1995.5
The reaction of enolates derived from titanium and boron complexes of beta-hydroxy ketones with aldehydes afforded aldol products in good to excellent yields. Whereas the boron mediated reactions gave exclusively anti aldol products derived from the reaction at C-alpha, the titanium mediated reactions produced primarily syn aldol products from reaction at C-alpha. The product selectivities observed in the titanium mediated aldol reactions were highly dependent on the substitution pattern of the starting beta-hydroxy ketone.