An n→π* interaction in aspirin: implications for structure and reactivity

J Org Chem. 2011 Oct 7;76(19):7933-7. doi: 10.1021/jo201389d. Epub 2011 Sep 6.


Stereoelectronic effects modulate molecular structure, reactivity, and conformation. We find that the interaction between the ester and carboxyl moieties of aspirin has a previously unappreciated quantum mechanical character that arises from the delocalization of an electron pair (n) of a donor group into the antibonding orbital (π*) of an acceptor group. This interaction affects the physicochemical attributes of aspirin and could have implications for its pharmacology.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspirin / chemistry*
  • Models, Molecular
  • Molecular Conformation
  • Physical Phenomena


  • Aspirin