87191-97-7

Upstream product

• 541-57-1 4-hydroxy-2(5H)-furanone 
• 552-89-6 2-nitro-benzaldehyde 

Downstream Products

• 65276-43-9 2,2,2-triethoxy-3-(2-nitro-phenyl)-3,6-dihydro-2H-2λ⁵-furo[3,4-d][1,2]oxaphosphol-4-one 
• 87192-18-5 10-(2-Nitrophenyl)-4,10-dihydro-1H,3H-furo<3,4-c><1,5>benzothiazepin-1-one 
• 92089-09-3 2-Methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro<3,4-b>pyridin-3-carbonsaeuremethylester 
• 87192-04-9 4-<(2-Nitrophenyl)methylene>-2,4-dihydro-5-(hydroxymethyl)-3H-pyrazol-3-one 
• 62760-69-4 2-Methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridin-3-carbonsaeureethylester 
• 195821-11-5 2-Methyl-4-(2-nitroso-phenyl)-5-oxo-5,7-dihydro-furo[3,4-b]pyridine-3-carboxylic acid methyl ester 
• 34785-00-7 2-Methyl-4-(2-nitrophenyl)-5-oxo-5,7-dihydrofuro<3,4-b>pyridin-3-carbonsaeuremethylester 
• 502770-35-6 2-Methyl-4-(2-nitrophenyl)-5-oxo-5,7-dihydrofuro[3,4-b]pyridin-3-carbonsaeureethylester 
• 502770-23-2 3-Acetyl-2-methyl-4-(2-nitrophenyl)-1,4,5,7-tetrahydrofuro[3,4-b]pyridin-5-on 
• 502770-38-9 3-Acetyl-2-methyl-4-(2-nitrophenyl)-5,7-dihydrofuro[3,4-b]pyridin-5-on 

Relevant academic research and scientific papers

3-(Nitrobenzylidene)-2,4(3H,5H)-furandiones in the Hantzsch pyridine synthesis, part 1.: A new approach to furo[3,4-b]pyridines

The nitrobenzylidenefurandiones 7 react with acetoacetic ester (8) and ammonium acetate or 3-aminocrotonic esters (9a, b) and 2-aminopent-2-en-4-on (9c), respectively heating in acetic acid to yield the tetrahydrofuro[3,4-b] pyridines 10. The dehydrogenation of 10 using nitric acid or activated manganese dioxide leads to the dihydrofuro[3,4-b]pyridines 12. When the reaction is carried out with the tetronic acid derivatives 7 and the enaminocarbonyl compounds 9 at 30°C in tert-butanol the hexahydro-7a-hydroxyfuro[3,4-b]pyridines 11 are obtained. Treating the N,O-acetales 11 with acetic anhydride in pyridine affords the annulated lactones 10.