Synthese von 1,2,3,4,5-Pentaisopropylcyclopentadien und 1,3,5-Tri-tert-butylcyclopentadien / Synthesis of 1,2,3,4,5-Pentaisopropylcyclopentadiene and 1,3,5-Tri-tert-butylcyclopentadiene

Abstract

Alkylation of tetraisopropylcyclopentadienyllithium (4b) gives a mixture of pentaisopropylcyclopentadiene isomers (1) which on metalation yields 11% pentaisopropylcyclopentadienylsodium (2). The mixture of products obtained on reacting 1,3-di-tert-butylcyclopentadienylsodium (6) with tert-butyliodide can be separated into 80% di-tert-butylcyclopentadiene and 9% 1,3,5-tritert-butylcyclopentadiene (7) by distillation.