公开(公告)号：DE4303647A1

公开(公告)日：1994-08-11

申请号：DE4303647

申请日：1993-02-09

Applicant: BASF AG

Inventor： LANGHAUSER FRANZ DR ,  SCHLUND RUEGER DR ,  LUX MARTIN DR ,  JUTZI PETER PROF DR ,  DAHLHAUS JUERGEN

IPC: C07C17/263 ,  C07C22/02 ,  C07C43/162 ,  C07C211/25 ,  C07C321/10 ,  C07C321/20

Abstract: Cyclopentadienes of the general formulae Ia to Ie in which the substituents and indices have the following meaning: R , R , R and R are C1- to C5-alkyl groups or C6- to C 15-aryl groups, X is NR R , OR , SR , Cl, Br or I, where R and R are hydrogen, C1- to C5-alkyl groups or C6- to C15-aryl groups and n is an integer from 2 to 5, and process for the preparation of cyclopentadienes of the general formulae IIa to IIe in which the substituents and indices have the following meaning: R , R , R and R are C1- to C5-alkyl groups or C6- to C 15-aryl groups, X is NR R , OR , SR , Cl, Br or I, where R and R are hydrogen, C1- to C5-alkyl groups or C6- to C15-aryl groups and m is an integer from 1 to 5, where in a first step lithium compounds of the general formula IIIa or IIIb or mixtures thereof and IIIc or IIId or mixtures thereof are converted with carboxylic acid esters of the general formula IV X(CH2)mCOOR in which R is a C1- to C4-alkyl group to dienols of the general formulae Va to Vd and the dienols of the general formulae Va to Vd are then converted by acid-catalysed ring closure to the cyclopentadienes of the general formulae IIa to IIe.