Acylation of a transient Ti(IV)-enolate by acyl halides and anhydrides. Facile synthesis of α-hydroxy-β-ketoesters
作者:Angelo Clerici、Laura Clerici、Ombretta Porta
DOI:10.1016/0040-4020(96)00621-7
日期:1996.8
Regioselective C-acylation at the carbonyl carbon of methyl phenylglyoxylate 1 occurs by reaction with a variety of acyl halides 3 and anhydrides 4 in the presence of TiCl3/py system in THF at room temperature. α-Hydroxy-β-ketoesters 5 are the only reaction products and pyridine is essential to obtain useful yields (50–90%). The mechanism of acylation involves the intermediacy of a nucleophilic a Ti(IV)-ene