Convergent domino Knoevenagel hetero-Diels-Alder and domino oxidation hetero-Diels-Alder reactions encountered in an unexpected formation of novel 5-aryl-1H-pyrano[2,3-d]pyrimidine-2,4(3H,5H)-diones and 5-aryl-2,3-dihydro-2- thioxo-1H-pyrano[2,3-d]pyrimidin-4(5H)-ones

摘要

Convergent domino Knoevenagel hetero-Diels-Alder and domino oxidation hetero-Diels-Alder reactions, in which both diene and dienophile are formed under the same reaction conditions in situ, are described for the first time, and their application is demonstrated by a one-pot synthesis of novel 5-aryl-1H-pyrano[2,3-d]pyrimidine-2,4(3H,5H)-diones and 5-aryl-2,3-dihydro-2- thioxo-1H-pyrano[2,3-d]pyrimidin-4(5H)-ones.