214545-59-2Relevant academic research and scientific papers
Ring Transformations of Heterocyclic Compounds. XVI [1]. Spiro[cyclohexadiene-dihydroacridines]. A Novel Class of Spirodihydroacridines by Ring Transformation of Pyrylium Salts with 9-Methylacridine and its Quaternary Salts
Zimmermann, Thomas,Abram, Ulrich,Schmidt, Klaus
, p. 787 - 793 (1998)
2,4,6-Triarylpyrylium salts 1 react with the in situ generated anhydrobase of 9,10-dimethylacridinium methosulfate (2a) in the presence of anhydrous sodium acetate in ethanol by a 2,5-[C4+C2] pyrylium ring transformation to give the
Separation and thermal racemization of the enantiomers of spiro[cyclohexadiene-dihydroacridines]
Zimmermann, Thomas,Pustet, Nikola,Mannschreck, Albrecht
, p. 1083 - 1090 (2000)
The enantiomers of substituted spiro[cyclohexadiene-dihydroacridines] were separated by enantioselective liquid chromatography with the sorbent/solvent systems triacetylcellulose/ methanol, tris-(3,5-dimethylphenylcarbamoyl)-cellulose/silica gel (Chiralcel OD)ln-heptane/2-propanol, and (+)-poly-(trityl methacrylate)/silica gel/n-heptane/2-propanol. Interconversion barriers of the enantiomers were determined for a series of derivatives by thermal racemization. Electrocyclic ring opening/ring closure in terms of the Woodward-Hoffmann rules is discussed for the enantiomerization mechanism; the interconversion of the enantiomers by enolization is ruled out by deuterium exchange experiments.
