Four 1-oxo-cycloalkan-2-ylideneacetic acids, differing in the size of the aliphatic ring and in the nature of the condensedunsaturated cycle, exhibit different reactivities towards hydrazine, leading in only one case to the desired tryciclic pyridazinone. The observed differences in behaviour cannot be ascribed to different configurations at the exocyclic double bond of the four acids: 1H NMR experiments, combined with UV photolysis, have shown that all compounds have been prepared in the E form and are stable in the absence of light and catalysts. The photochemically obtained Z isomers show an increasing tendency to form tricyclic lactones with increasing size ofthe aliphatic ring. A theoretical structural analysis of the E and Z isomers, the tricyclic lactones and some of the hypothetical intermediates of the reaction with hydrazine suggests the size of the aliphatic ring and the associated flexibility to be crucial in modulating the ability of these compounds to form tricyclic products.

Structures and reactivities of 1-oxo-cycloalkan-2-ylidenacetic acids. A 1H-NMR, modeling and photochemical study / S., Ghelli; L., Toma; D., Barlocco; Costi, Maria Paola; Ponterini, Glauco. - In: TETRAHEDRON. - ISSN 0040-4020. - STAMPA. - 56:(2000), pp. 7561-7571.

Structures and reactivities of 1-oxo-cycloalkan-2-ylidenacetic acids. A 1H-NMR, modeling and photochemical study

COSTI, Maria Paola;PONTERINI, Glauco
2000

Abstract

Four 1-oxo-cycloalkan-2-ylideneacetic acids, differing in the size of the aliphatic ring and in the nature of the condensedunsaturated cycle, exhibit different reactivities towards hydrazine, leading in only one case to the desired tryciclic pyridazinone. The observed differences in behaviour cannot be ascribed to different configurations at the exocyclic double bond of the four acids: 1H NMR experiments, combined with UV photolysis, have shown that all compounds have been prepared in the E form and are stable in the absence of light and catalysts. The photochemically obtained Z isomers show an increasing tendency to form tricyclic lactones with increasing size ofthe aliphatic ring. A theoretical structural analysis of the E and Z isomers, the tricyclic lactones and some of the hypothetical intermediates of the reaction with hydrazine suggests the size of the aliphatic ring and the associated flexibility to be crucial in modulating the ability of these compounds to form tricyclic products.
56
7561
7571
Structures and reactivities of 1-oxo-cycloalkan-2-ylidenacetic acids. A 1H-NMR, modeling and photochemical study / S., Ghelli; L., Toma; D., Barlocco; Costi, Maria Paola; Ponterini, Glauco. - In: TETRAHEDRON. - ISSN 0040-4020. - STAMPA. - 56:(2000), pp. 7561-7571.
S., Ghelli; L., Toma; D., Barlocco; Costi, Maria Paola; Ponterini, Glauco
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

Licenza Creative Commons
I metadati presenti in IRIS UNIMORE sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono rilasciati con licenza Attribuzione 4.0 Internazionale (CC BY 4.0), salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11380/306846
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 8
  • ???jsp.display-item.citation.isi??? ND
social impact