Meldrums Acid as Synthetic Equivalent

SCHEME 13.95 Synthesis of 3,4-dihydropyranones 454/458 starting from 1,3-dicarbonyl compounds 15/47/455/456. 

SCHEME 13.96 Synthesis of 3,4-dihydropyranones 460/463 starting from stable enols 37/461. 

4- dihydropyridine synthesis (see Section 13.5.3), the addition of ammonium acetate [190] or primary amines [57] led to the incorporation of a nitrogen atom and therefore to a broad range of 

Comparable to the synthesis of 3,4-dihydropyranones, preformed enamines 104/485 [191] and arylamines 125 [192] 

SCHEME 13.97 Synthesis of 3,4-dihydropyranones 466 starting from barbituric acids 61/464. 

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