The Effect of Lewis Acids on the Cycloaddition of 3, 3, 6‐Trimethylcyclohex‐5‐ene‐1, 2, 4‐trione: Hydrogen Transfer versus Cycloaddition with Cyclopentadiene. Issue 23 (26th June 2013)

• Record Type: Journal Article
• Authors: Eddy, Nicholas A.; Richardson, Jay J.; Fenteany, Gabriel
• Is Part Of: European journal of organic chemistry. Issue 23(2013)
• Page Start: 5041
• Page End: 5044
• Publication Date: 2013-06-26
• Subjects: Lewis acids -- Lewis acid catalysis -- Hydrogenation -- Cycloaddition -- Ket­ones; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201300706
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: Exposure of 3, 3, 6‐trimethylcyclohex‐5‐ene‐1, 2, 4‐trione to catalytic amounts of Lewis acids revealed two disparate reactions in the presence of cyclopentadiene. The expected cycloaddition was found to be reversible for the title compound, and transfer hydrogenation was the preferred pathway over long periods of time. Other tested substrates were able to undergo facile cycloaddition with considerable yields and without the parallel reduction. Abstract : The work presented here defines the effect of Lewis acid catalysts on the reaction between cyclopentadiene and 3, 3, 6‐trimethylcyclohex‐5‐ene‐1, 2, 4‐trione. Cycloaddition and hydrogenation reactions both occur in parallel. For cycloaddition, the dr was similar for all Lewis acids tested. Hydrogenation was catalyzed efficiently by AlCl3 and found to be the main mode of reaction for this particular system.