Natural and synthetic 2H-pyran-2-ones and their versatility in organic synthesis

Mechanistic Insights into Ring-Opening and Decarboxylation of 2-Pyrones in Liquid Water and Tetrahydrofuran

“…We recently demonstrated that hydrogenation of 1 over a Pd catalyst provides access to 3 and 6, and these three 2-pyrones can be converted to bifunctional chemicals including 2,4-pentanedione (2), 3-penten-2-one (4), 4-hydroxypentanone (5), and sorbic acid (8). 1 Surprisingly, we observed for the first time the thermally activated ring-opening and decarboxylation 4-hydroxy-6-methyl-2-pyrone/triacetic acid lactone (1); 2,4-pentanedione (2); 5,6-dihydro-4-hydroxy-6-methyl-2H-pyran-2-one (3); 3-penten-2-one (4); 4-hydroxypentanone (5); 4-hydroxy-6-methyltetrahydro-2-pyrone (6); parasorbic acid (7); sorbic acid (8); 1,3-pentadiene (9).…”

“…Additionally, it is notable that besides their potential as platform chemicals, 2-pyrones of natural and synthetic origin, including 1, have been demonstrated to possess synthetic potential and versatility as building blocks for aromatics 7 and bioactive compounds. 8 Therefore, this work provides guidance in the selection of conditions (e.g., solvent, temperature) for conversion of these compounds.…”

<strong>CATALYSIS INVESTIGATION FOR SYNTHESIS OF 2-AMINO-4<em>H</em>-PYRAN-3-CARBONITRILES CONTAINING PROPARGYL GROUP</strong>

“…These compounds have the wide range of biological activities and therapeutics. 4H-pyran derivatives well distributed in many naturally occurring compounds [1]. Organic compounds containing 4H-pyran ring shown biologically activities, such as antimicrobial [2], anti-inflammatory [3], anticancer [4], etc…The synthesis of some propargylic ethers of 2-amino-4H-chromene-3-carbonitriles was reported in our previous paper [5] from resorcinol, malononitrile and benzaldehydes by three-component one-pot reaction.…”

Palladium-catalyzed synthesis of novel tetra- and penta-cyclic biologically active benzopyran- and pyridopyran-containing heterocyclic systems

“…[1][2][3] The synthesis and reactions of pyrans and benzopyrans have been well reviewed. [4][5][6][7][8][9] Recently the uses and properties of important natural and synthetic 2H-pyran-2-ones in organic synthesis were documented. 8,9 One of the earliest works describing the synthesis of the pyranothiazole ring from 3,5-dibromopyran-4-one and a thioamide was published in 1948.…”

“…[4][5][6][7][8][9] Recently the uses and properties of important natural and synthetic 2H-pyran-2-ones in organic synthesis were documented. 8,9 One of the earliest works describing the synthesis of the pyranothiazole ring from 3,5-dibromopyran-4-one and a thioamide was published in 1948. 10 Some methods for the preparation of 2-substituted [1]benzopyrano [3,4-d]-thiazol-4-ones and -imidazol-4-ones are documented.…”