SYNTHESIS OF 3-COUMARIN-CARBOXYLIC ACIDS AND THEIR APPLICATION IN THE TOTAL SYNTHESIS OF AIAPIN, COUMARIN, AND UMBELIFERONE

摘要

The synthesis of 3-coumarin-carboxylic acids and their application to the total synthesis of the natural products ayapin, coumarin, and umbeliferone in undergraduate organic chemistry experiments is described herein. The synthetic approach consists of a one-pot cyclization between salyciladehydes and Meldrum's acid in water to produce the above mentioned acids, followed by decarboxylation under basic or radical conditions.