ACID-MEDIATED CYCLOTRANSFORMATIONS OF 4a-SUBSTITUTED 4H-4a,5-DIHYDROINDENO[1,2-<i>b</i>]PYRIDINES AS A NEW ROUTE TO 9a-SUBSTITUTED 1H-FLUORENES

Authors

  • S. Stupnikova Latvian Institute of Organic Synthesis Riga LV-1006
  • Dz. Muceniece Latvian Institute of Organic Synthesis Riga LV-1006
  • V. Lūsis Latvian Institute of Organic Synthesis Riga LV-1006

DOI:

https://doi.org/10.1007/7677

Keywords:

4a-substituted 1H-4a, 5-dihydroindenopyridines, 9a-substituted 1H-fluorenes, methanobenzo[a]azulene, cyclotransformation, recyclisation

Abstract

4a-Substituted dihydroindenopyridines undergo cleavage of the C(9b)=N bond in water-containing acidic medium, resulting in the formation of diastereomeric ethyl  α-acetyl-β-(2,3-dihydro-1,3-dioxo-1H-inden-2-yl)-β-phenylpropionates and 9a-substituted 1,9a-dihydrofluore-
none derivatives. The cyclisation of α-acetyl-β-(2,3-dihydro-1,3-dioxo-1H-inden-2-yl)-β-phenyl-
propionates with benzylammonium acetate affords 3-benzylamino-1,9a-dihydrofluorenones. The methanobenzo[a]azulene compound is also found among cyclisation products.

How to Cite
Stupnikova, S.; Muceniece, Dz.; Lūsis, V.  Chem. Heterocycl. Compd. 2007, 43, 197. [Khim. Geterotsikl. Soedin. 2007, 249.]

For this article in the English edition see DOI 10.1007/s10593-007-0032-y

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Published

2023-04-03

Issue

No. 2 (2007)

Section

Original Papers