Novel Short-Step Synthesis of Functionalized γ-Phenyl-β-hydroxybutenoates and their Cyclization to 4-Hydroxycoumarins via the <i>N</i>-Hydroxybenzotriazole Methodology
A novel method for the synthesis of functionalized 3- substituted 4-hydroxycoumarins is reported. C-Acylation com- pounds were derived from the reaction of the N-hydroxybenzotri- azole ester of the functionalized acetyl salicylic acids and a variety of active methylene compounds and cyclized to the title com- pounds. The synthesis is simple and the compounds are produced in yields varying from 39 to