In acid or basic condition the recyclization of the opening product was carried out, and spirocyclic and bridged compounds 11～14 were obtained by intramolecular Claisen condensation.

Investigation on activity of Claisen-Schmidt condensation reaction for different substituted benzaldehyde compounds;

Investigation of Claisen-Schmidt condensation reaction using near-critical water as media indicated that the reaction can be carried out in near-critical water without any added catalyst.

Sodium diethyl oxalacetate was prepared by Claisen condensation of diethyl oxalate with ethyl acetate.

Sodium diethyl oxalacetate was prepared by Claisen condensation with acetic and oxalic acid esters.

Two new β-diketones containing trifluoromethyl groups,4,4,4-trifluoro-1-(6-methoxynaphthalen-2-yl)butane-1,3-dione and 4,4,4-trifluoro-1-(4-phenylmethoxyphenyl)butane-1,3-dione were synthesized from aromatic ketones and ethyl trifluoracetate by the classical Claisen condensation reaction using CH3ONa as the strong base.

Two UV-A ultraviolet absorbents:1-(4-methoxy-phenyl)-3-phenylpropane-1,3-dione and 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl) propane-1,3-dione were synthesized from aromatic ketone and ester by classical Claisen condensation using NaNH_2 as strong alkali.

In the reaction process,the intermediate phenyl-1-nitrilebenzylketone obtained by Claisen condensation in basic condition was not separated from the reaction mixture,but used directly to synthesize the targeting molecule by hydrolyzing in 48% HBr solution.

Piperonylene propanal was synthesized through Claisen-Schmidt condensation reaction in the presence of KF/Al2O3,heliotropin and propanal as reactants.

A series of substituted-2 -hydroxychalcone in yields of 48%～90% were synthesized by Claisen-Schmidt condensation from substituted 2 -hydroxyhypnone and substituted benzaldehyde under room temperture.

Via Claisen-Schmidt condensation and hydrogenation reaction, raspberry ketone was synthesized by using p-hydroxybenzaldenhyde as the main raw material.