76782-20-2

Upstream product

• 78999-94-7 (E)-5-Benzoyl-6-dimethylamino-2,4-dioxo-hex-5-enoic acid ethyl ester 
• 93-91-4 1-phenylbutan-1,3-dione 
• 129118-10-1 2-[(dimethylamino)methylene]-1-phenyl-1,3-butanedione 
• 76782-19-9 ethyl 5-benzoyl-4-oxo-4H-pyrane-2-carboxylate 

Downstream Products

• 76782-21-3 ethyl 5-hydroxy-4-oxo-6-phenyl-4H-pyran-2-carboxylate 
• 76782-17-7 Ethyl 5-chloro-4-oxo-6-phenyl-4H-pyran-2-carboxylate 
• 79008-38-1 5-Oxo-2,7-dioxa-bicyclo[4.1.0]hept-3-ene-3,6-dicarboxylic acid 3-ethyl ester 6-phenyl ester 

Relevant academic research and scientific papers

THE SYNTHESIS AND REARRANGEMENT OF EPOXYPYRONES

The oxidation of 5-acyl-4-oxo-pyran-2-carboxylic acid esters 1,2 to novel epoxypyrones and subsequent rearrangement to the previously inaccesible 6-substituted-5-hydroxy or 5-chloropyrones 6 - 9 are described.

6-Substituted pyranone compounds and their use as pharmaceuticals

Compounds are described of the formula STR1 in which R1 is COOR5, CONHR5, cyano, 5-tetrazolyl or R6, where R5 is hydrogen or C1-8 alkyl and R6 is phenyl or naphthyl, the phenyl or naphthyl group being optionally substituted by one or more group selected from halogen, C1-6 alkyl, C1-4 alkoxy, hydroxy, benzyloxy, nitro, trifluoromethyl, carboxyl, C1-4 alkylsulphinyl, C1-4 alkylsulphonyl, N(R5)2, NHCOR5 and SR5 ; R2 is R6 or --CH=CH--R6 when R1 is COOR5, CONHR5, cyano or 5-tetrazolyl, or R2 is --CH=CH--R6 when R1 is R6 ; R3 is hydrogen, C1-6 alkyl, halogen, hydroxy or --OCH2 R6 ; and R4 is hydrogen, C1-6 alkyl or halogen; and salts thereof. The compounds have pharmaceutical properties and in particular are useful in the treatment of immediate hypersensitivity conditions such as asthma.