- 2,7-Dimethyl-4H-pyrano-2H-pyran-4,5-dione, a Novel Product in the Base-catalysed Self-condensation of Ethyl Acetoacetate : Carbon-13 NMR Spectral Studies
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Self-condensation of ethyl acetoacetate (EAA) in the presence of a small amount of sodium bicarbonate affords, in addition to the earlier reported dehydroacetic acid (II) (45 percent), a new fused γ-pyrono-pyrone derivative in 40 percent yield, the structure of which has been shown to be 2,7-dimethyl-4H-pyrano-2H-pyran-4,5-dione (III) mainly based on PMR and 13C NMR spectral results and supported by UV, IR and mass spectral data.Compound (II) upon refluxing with EAA in water containing pyridine gives III while EAA under similar condition neither affords II nor III and remains mostly unchanged, supporting the postulated mechanism of formation of III via II. 13C NMR spectral data of II have also been discussed.
- Talapatra, Sunil K.,Basak, Amit,Maiti, Bhim C.,Talapatra, Bani
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p. 546 - 548
(2007/10/02)
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