Abstract:
:The electronic circular dichroism (ECD) spectra of two sesquiterpenoids (1 and 2) related to oplopanone, obtained from a methanolic extract of the plant Serphidium stenocephalum (Artemisia stenocephala), were measured and reproduced by means of time-dependent density functional theory (TDDFT) calculations, establishing their absolute configuration. The application of ketone octant rule for carbonyl n-π* ECD band to compounds 1 and 2, which include an acyclic carbonyl group, was critically assessed. The peculiar oplopanone skeleton makes a straightforward application of the octant rule impossible, because of the uncertainty related to the shape of the so-called third nodal surface separating front and back octants. The various group contributions to the carbonyl n-π* ECD band were estimated with TDDFT calculations on selected molecular models obtained by consecutive dissections from 1.
journal_name
Chiralityjournal_title
Chiralityauthors
Shafiq N,Saleem M,Riaz N,Tousif MI,Jabbar A,Tareen RB,Pescitelli Gdoi
10.1002/chir.22263subject
Has Abstractpub_date
2014-01-01 00:00:00pages
39-43issue
1eissn
0899-0042issn
1520-636Xjournal_volume
26pub_type
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