ChemInform Abstract: Ytterbium Triflate Catalyzed Conjugate Addition of β‐Ketoesters to Activated 1,4‐Naphthoquinones.

Abstract

Benzofuran derivatives R 0070Ytterbium Triflate Catalyzed Conjugate Addition of β-Ketoesters to Activated 1,4-Naphthoquinones. -The reaction is strongly sensitive to the nature of solvent and reaction time. The reaction of β-ketoesters (VI) in MeCN provides a mixture of diastereomers after 30-45 min and leads directly to the dehydrated products after 90 min. -(MUDIGANTI, N. V. S.; CLAESSENS, S.; DE KIMPE*, N.; Tetrahedron 65 (2009) 8, 1716-1723; Dep. Org. Chem., Fac. Biosci. Eng., Univ. Gent, B-9000 Gent, Belg.; Eng.) -Y. Steudel 23-105