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Interaction between Oxygen Lone‐Pair Orbitals of Ether and α,β‐Unsaturated Ketone Functions in 3,5,6‐Trimethylidene‐7‐oxabicyclo[2.2.1]heptan‐2‐one and 3,6‐Dimethylidene‐7‐oxabicyclo[2.2.1]heptane‐2,5‐dione: A PE‐Spectroscopic Investigation
Author(s) -
Röser Karl,
Carrupt PierreAlain,
Vogel Pierre,
Honegger Evi,
Heilbronner Edgar
Publication year - 1990
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19900730102
Subject(s) - chemistry , lone pair , heptane , ozonolysis , ketone , ether , ab initio , atomic orbital , molecular orbital , bicyclic molecule , medicinal chemistry , computational chemistry , organic chemistry , molecule , physics , quantum mechanics , electron
Controlled ozonolysis of 2,3,5,6‐tetramethylidene‐7‐oxabicyclo[2.2.1]heptane ( 1 ) afforded 3,5,6‐trimethylidene‐7‐oxabicyclo[2.2.1]heptan‐2‐one ( 2 ). Ozonolysis of 2 gave a 1:1 mixture of 3,5‐dimethylidene‐7‐oxa‐bicyclo[2.2.1]heptane‐2,6‐dione ( 3 ) and 3,6‐dimethylidene‐7‐oxabicyclo[2.2.1]heptane‐2,5‐dione ( 4 ). The He(Iα) photoelectron (PE) spectra of 2 and 4 have been recorded. Comparison with the PE data of related systems, and with the result of ab initio STO‐3G calculations, confirm the existence of significant through‐bond interactions between the oxygen lone‐pair orbitals n(CO) of the carbonyl functions and n(O) of the O(7) ether bridge.