ChemInform Abstract: Aldol Reaction and Robinson‐Type Anellation Catalyzed by Lanthanoid Triisopropoxides.

Abstract

Aldol Reaction and Robinson-Type Anellation Catalyzed by Lanthanoid Triisopropoxides.-Lanthanoid triisopropoxides are active catalysts for aldol reactions. Among the lanthanoid catalysts tested, the La derivative exhibits the highest efficiency in the aldol reactions. It is superior to Al(OiPr)3 and even iPrONa. Aldehydes give the correspondig β-hydroxyaldehydes (cf. (II)/(III); (V)) in good yields under mild conditions. Monoketones prove to be less reactive but furnish condensation products (cf. (VII)), whilst diketones such as (VIII) easily undergo cyclizations. The lanthanoid triisopropoxides are also suitable catalysts for Robinson-type anellations (→(XII)). -(OKANO, T.; SATOU, Y.; TAMURA, M.; KIJI, J.; Bull. Chem.