Title: Synthesis of Some Spirochroman-4-Ones by Regioselective [4+2] Cycloaddition Reactions
Volume: 4
Issue: 3
Author(s): Moheddine Askri, Mohamed Rammah, Karin Monnier-Jobe, Kabula Ciamala, Michael Knorr and Carsten Strohmann
Affiliation:
Keywords:
[4+2] Cycloaddition, regiochemistry, pyrroles, spiro-compounds, 3-aryliden-4-chromanones, Reissert salt
Abstract: Synthesis of several spiro[4-aryl-5-hydroxy-2-(1-isoquinolinyl)-5-phenyl-4,5-dihydro-3H-pyrrole- 3,3-3H-chroman-4-ones] has been accomplished in satisfying yields by regioselective [4+2] cycloaddition reaction of a 2-benzoyl-1,2-dihydroisoquinoline-1-carbonitrile tetrafluoroborate salt across (E)-3-arylidene-4- chromanones. The spirocompounds evolve to pyrroles after acidic hydrolysis. The crystal structure of (10c) has been determined by an X-Ray study diffraction.