ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The He(I) PE spectra of 1,3-dioxepine (1) and the related bicyclic acetals 1,3,7,7-tetramethyl-2,11-dioxabicyclo[4.41]undeca-3,5-dien-10-one (2) and 1,3,7,7-tetramethyl-10-methylidene-2,11-dioxabicyclo[4.4.1]undeca-3,5-diene (3) have been recorded and analyzed. Interpretation of the PE data indicate strong orbital interactions between the diene and acetal moieties in 1. Different conformations have been evaluated by a joint MMP2 molecular mechanics and ab initio molecular orbital analysis, which shows 1 to prefer a slightly boat-shaped conformation with the diene part being planar and the CH2 group placed considerably out-of-plane. The bicyclic acetals 2 and 3 show a frontier orbital picture similar to 1 superimposed with the characteristics of the C=O and C=C groups, respectively. The crystal structure of the keto-acetal 2 was determined by an X-ray analysis.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19850680809
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