Application of Baylis-Hillman methodology in the synthesis of coumarin derivatives

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 alpha,beta-unsaturated ester intermediates.