Cyclooctadecanonaene

  [18]annulene is an annulene with chemical formula C₁₈H₁₈. This hydrocarbon obeys the Hückel's rule and is therefore an aromatic compound. The compound was first synthesised by F. Sondheimer. The original synthesis started by trimerization of the di-alkyne 1,5-hexadiyne with copper(II) acetate in pyridine followed by deprotonation and isomerization with potassium tert-butoxide in tert-butanol and was concluded with hydrogen organic reduction with the Lindlar catalyst.

Additional recommended knowledge

Daily Visual Balance Check

Weighing the right way

Essential Laboratory Skills Guide

Notes

1. In the literature and some internet references Sondheimer is misspelled as Sandheimer.