Bicyclo[3.2.1]octa‐2,6‐dienylkalium. Synthese aus dem Dien und 13 C‐NMR‐Spektrum

Abstract

Bicyclo[3.2.1]octa-2,6-dienylpotassium. Synthesis from the Diene and 13C NMR Spectrum Bicyclo[3.2.1]octa-2,6-dienylpotassium (2) has been obtained as a lemon-coloured powder by treating bicyclo[3.2.1]octa-2,6-diene (1) with an excess of n-butyllithium/potassium tert-butoxide in THF. The 13C NMR shifts show that homohyperconjugation in 2 is small. However, a charge transfer from the allylic to the olefinic part is clearly indicated by high field shifts of the olefinic carbon signals and a reduced splitting of the allylic carbon signals. The shifts agree well with an earlier ab initio study. C-H couplings are shown to be another probe for the charge delocalization in 2.