One-Pot Synthesis of Some Fused Pyran-2-ones
1995; Elsevier BV; Volume: 41; Issue: 6 Linguagem: Inglês
10.3987/com-95-7062
ISSN1881-0942
AutoresMarijan Kočevar, Vladimir Kepe, Slovenko Polanc,
Tópico(s)Organic Chemistry Synthesis Methods
ResumoAbstrnct -A one-pot synthesis of different fused pyran-2-ones starting from some less commonly used activated methylene compounds (cyclic lactones, a thiolactone and a lactam), one-carbon sources and N-acylglycines in acetic anhydride is described.There are numerous synthetic methods for the preparation of 2H-pyran-2-ones and fused pyran-2-ones.'Some recent papers are dealing with a simple one-pot synthesis of several acylamino derivatives of this type starting from 1.3-dicarbonyl compounds, one-carbon synthons, such as triethyl orthoformate (TOF), diethoxymethyl acetate (DEMA) or N,N-dimethylformamide dimethyl acetal (DMFDMA), N-acylglycines and a large excess of acetic anhydridezd Since this method seems to be the simplest way for the synthesis of several pyranone ring containing systems, we have tried to find its further applications.For this reason we have applied our method to less commonly used 1,3-dicarbonyl compounds, such as tetronic acid (I), thiotetronic acid (2), 4-hydroxy-6-methyl-2H-pyran-2-one (3), 4-hydroxy-2H-1-benzopyran-2-one (4) and 4-hydroxyquinolin-2(1H)-one (5).They all possess an unsymmetrically substituted diactivated methylene group and might exist in two or more tautomeric forms.
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