The Synthesis of Some Dimethylpyranocoumarins and Isopropenyldihydrofuranocoumarins

Abstract

Abstract Two pyranocoumarins, 7,7-dimethyl-2(7H)-benzo[1,2-b:4,5-b′]dipyranone and 8,8-dimethyl-2(8H)-benzo[1,2-b:5,4-b′]dipyranone, and three dihydrofuranocoumarins, 2-isopropenyl-1,2-dihydro-8-furo[1,2-f][1]benzopyranone, 2-isopropenyl-2,3-dihydro-6-furo[1,2-e][1]benzopyranone, and 2-isopropenyl-2,3-dihydro-7-furo[2,1-e][1]benzopyranone, were synthesized by an effective pyrone-ring formation in corresponding o-hydroxybenzaldehyde derivatives. And, 2-[1-(hydroxymethyl)vinyl]-1,2-dihydro-8-furo[1,2-f][1]benzopyranone was also synthesized selenium dioxide oxidation.