Does the DABCO-catalysed reaction of 2-hydroxybenzaldehydes with methyl acrylate follow a Baylis-Hillman pathway?

摘要

Evidence is presented which supports the intermediacy of dipolar Baylis-Hillman-type adducts in the synthesis of coumarin and chromene derivatives from the reaction of 2-hydroxybenzaldehydes with methyl acrylate in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO).