Ringtransformationen heterocyclischer Verbindungen. VII. 2,4,5-Triaryl-benzophenone aus 2,4,6-Triaryl-pyryliumsalzen und Arylacetaldehyden: Erste Pyryliumringtransformationen mit Aldehyden als Kohlenstoffnucleophile
作者:T. Zimmermann
DOI:10.1002/prac.19943360405
日期:——
2,4,6-Triarylpyrylium salts 1 react with arylacetaldehydes 2 in the presence of sodium acetate in ethanol by a 2,5-[C4+C2] ring transformation to give 2,4,5-triarylbenzophenones 3 in high yield, Besides the sodium acetate, sodium methanolate, triethylamine, triethylamine/acetic acid or piperidine acetate can be applied as condensing agent. The reaction represents the first pyrylium ring transformation initiated by aldehydes.
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