One-Pot Synthesis of β,β-Disubstituted α,β-Unsaturated Carbonyl Compounds.

TiCl4-promoted aldol reaction of ketones as aldol acceptors followed by elimination of the titanoxy group from the Ti-aldolates affords β,β-disubstituted α,β-unsaturated carbonyl compounds in a one-pot procedure. The use of additives, such as DMF, N,N,N',N'-tetramethylethylenediamine, and pyridine, in the elimination step was found to be important.