MgBr₂‐Mediated Ionic Diels–Alder Reaction of Acetals of α,β‐Unsaturated Aldehydes and Ketones with 1,3‐Dienes

Abstract

A facile, mild, and efficient methodology for the ionic Diels–Alder reaction of acetals of α,β‐unsaturated ketones and aldehydes as dienophiles with various 1,3‐dienes employing MgBr₂ as the Lewis acid catalyst to furnish corresponding Diels–Alder adducts at ambient temperature is described.

Keywords:

• acetals
• catalysts
• Diels–Alder reactions
• dienes

Acknowledgments

Presented in part at the National Symposium in Chemistry, January 27–30, 1999, Indian Institute of Science (IISc). Banglore, India. One of us (K. S. Ethiraj) thanks Council of Scientific and Industrial Research (CSIR), New Delhi (India), for the award of a fellowship. Funding under Young Scientist Award (YSA) scheme from CSIR, India, is gratefully acknowledged. We are thankful to T. Ravindranathan for encouragement.