ChemInform Abstract: Enantioselective 6‐endo‐trig Wacker‐Type Cyclization of 2‐Geranylphenols: Application to a Facile Synthesis of (‐)‐Cordiachromene.

Abstract

Enantioselective 6-endo-trig Wacker-Type Cyclization of 2-Geranylphenols: Application to a Facile Synthesis of (-)-Cordiachromene. -Palladium-catalyzed intramolecular oxidative Wacker-type cyclization of o-geranylphenols (I) predominantly provides access towards chromenes (II) via a 6-endo-trig pathway. The products are obtained in moderate yields and stereoselectivities. This method is applied to a direct protecting-group-free synthesis of cordiachromene (V), although stoichiometric amounts of Pd complex and ligand are necessary. -(TAKENAKA, K.; TANIGAKI, Y.; PATIL, M. L.; RAO, C. V. L.; TAKIZAWA, S.; SUZUKI, T.; SASAI*, H.; Tetrahedron: Asymmetry 21 (2010) 7, 767-770,