Infrared spectra and theoretical study of methyl, formyl and acetyl derivatives of chromones
作者:Hafen Mohamad El-Metwally El-Shaaer、Alexander Perjéssy、Pavol Zahradník、Margita Lácová、Zora Šusteková
DOI:10.1007/bf00819522
日期:1993.5
The C=O stretching frequencies of substituted 2-methylchromones (3a-3j). 2-formylchromones (4a-4j), 3-formylchromones (5a-5j) and 3-acetyl-2-methylchromones (6a-6i) were measured in CCl4 and CHCl3 and correlated with sigma+ substituent constants. Using the results of the infrared spectral investigation and the theoretical calculations by the semiempirical AM1 method, the conformation and the transmission of electronic effects in compounds 4-6 were studied. For the 2-substituted chromone system the transmission factory gamma according to the definition of Charton was determined. The preparation of some new 2-methylchromones (3e-3j) and 3-(2,2-diformyl-chlorovinyl)-6-methylchromone (7) is also described.