1H and 13C NMR Chemical shift assignments of a cyclopentane-fused cis-azetidinone (cis-azabicyclo[3.2.0]heptan-7-one). A theoretical and experimental investigation
Year: 2002
Type: article
Abstract: The 1 H and 13 C NMR chemical shifts of cyclopentane-fused cis-azetidinone (cisazabicyclo[3.2.0]heptan-7-one) were determined with the help of full spectral analysis.The geometry and electronic structure of the molecule were investigated at both the RHF and the B3LYP level with different basis sets.The NMR data were calculated by means of the GIAO, CSGT and IGAIM methods.All quantum-chemical calculations, including those of NMR data, were performed by ab initio level RHF and DFT methods.The geometry optimization resulted in an envelope-type conformation, while the four-membered heterocycle proved to be planar.Excellent agreement between the theoretical and experimental results was found for the RHFlevel 1 H chemical shifts and for the B3LYP-type 13 C chemical shifts.The experimental spectra revealed equivalent methylene protons at position 5, indicating that the cyclopentane ring has a high degree of conformational freedom at this carbon.
Source: ARKIVOC
Institutions: University of Szeged, Hungarian Academy of Sciences
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W2103036697