title: A new protocol for a regioselective aldol condensation as an alternative convenient synthesis of beta-ketols and alpha,beta-unsaturated ketones.
abstract: A general and convenient synthesis of beta-ketols and alpha,beta-alkenones has been achieved by a Knoevenagel condensation of a beta-ketoacid with an aldehyde in aqueous medium. Saponification of a beta-ketoester by an aqueous KOH 10% solution gives the potassium salt of the beta-ketoacid, which is condensed in situ with an aldehyde at pH 7.8-8.0, at 60 degrees C for 5-6 h. The intermediate beta-ketocarboxylate is smoothly decarboxylated in the reaction medium, giving the beta-ketol in high yield (75-90%). Acidification of the reaction mixture at pH 1 and heating at 70 degrees C under vigorous stirring for 6 h, leads directly to the corresponding alpha,beta-unsaturated ketone in good yield (65-75%).
authors.affiliation: Vioryl S.A. Research Department, Kato Kifissia, 14564 Athens, Greece.
authors.forename: Therapia
authors.initials: T
authors.lastname: Kourouli
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Kefalas
authors.forename: Nikitas
authors.initials: N
authors.lastname: Ragoussis
authors.forename: Valentine
authors.initials: V
authors.lastname: Ragoussis