Abstract
A general, chemoselective approach to 3-substituted coumarins via Baylis–Hillman reactions of O-benzylated salicylaldehyde precursors has been demonstrated. Competitive cyclization to chromene derivatives is inhibited by conjugate addition of benzylamine or piperidine to the α,β-unsaturated ester intermediates.
Acknowledgment
The authors thank the National Research Foundation (NRF) and Rhodes University for generous financial support.