Regioselective alkylations of cyclic 1,3-diketones via metalated dimethylhydrazones

Date

1997-01-01

Author

Demir, Ayhan Sıtkı
Enders, D

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Cyclic 1,3- diketones 1 are transformed into their 2,2-dimethylhydrazones 2, which can be alkylated regioselectively at different positions after mono-, di-, tri-, and tetrametalation. Monometalated C-2 unsubstituted hydrazones afford C-2 and N-alkylation, monometalated C-2 substituted hydrazones afford only C-2 alkylation. The regioselectivity of the alkylation of the polymetalated hydrazones follows Hauser's rule according to the sequence: NH- > C-4 Ha > C-5 > C-4 Hb. Hydrolysis of the product hydrazones 3-5 afforded mono-and polyalkylated 1,3- diketones 7 in good yields.

Subject Keywords

Metallated dimethylhydrazones, General synthesis , Beta-diketones, C-alkylation, Dianions

URI

https://hdl.handle.net/11511/57391

Journal

JOURNAL FUR PRAKTISCHE CHEMIE-CHEMIKER-ZEITUNG

DOI

https://doi.org/10.1002/prac.19973390199

Collections

Department of Chemistry, Article

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Regioselective alkylation of dianions of cyclic 1.3-diketones via their monodimethylhydrazones. Synthesis of C-4 substituted cyclic 1.3-diketones Enders, Dieter; Demir, Ayhan Sıtkı (Elsevier BV, 1989-1) Cyclic 1.3-diketones are transformed into the corresponding monodimethylhydrazones, which can be alkylated regioselectively at C-4 via dianions with various alkyl halides. The regioselective alkylation of cyclic 1.3-diketones 1, to 4-substituted derivatives 4 is described.
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Citation Formats

A. S. Demir and D. Enders, “Regioselective alkylations of cyclic 1,3-diketones via metalated dimethylhydrazones,” JOURNAL FUR PRAKTISCHE CHEMIE-CHEMIKER-ZEITUNG, pp. 553–563, 1997, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57391.