Ytterbium triflate hydrate catalyzed Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds

A novel preparation of 5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran derivatives promoted by lnCl 3 .4H 2 O,TMSCl in ionic liquid ([bmin]BF 4 ) is described. The preparative procedure presented in this paper is operationally simple and environmentally friendly. The reaction media and catalyst used can be recovered and reused for at least four times without loss in the catalytic activity. This method is promising for a mass-production process.

R. Aggarwal

Papers

An efficient and simple one-pot synthesis of 2,4-diaryl-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4h-1-benzopyrans

An Efficient and Simple One-Pot Synthesis of 2,4-Diaryl-7,7-dimethyl-5- oxo-5,6,7,8-tetrahydro-4H-1-benzopyrans