Patent ID: 6235925
Filing Date: 2001-05-22
Classification: C07C

Abstract:
Process for preparing a .alpha.-substituted ring system of the formula (II) ##STR6##wherein, in each case independently of one another,R is one or more organic substituents,R.sup.1 is --COR.sup.2, --SO.sub.2 PhR.sup.2, --COOR.sup.2, CONRR.sup.2, CONRR, tert-butyl, PR.sub.2 or PR.sup.2.sub.2, hydrogen orR which is bound to the nitrogen in formula (II) and R.sup.1 form together a cyclic group having the formula ##STR7##R.sup.2 is alkyl, aryl,andn represents the numbers 1, 2, 3 or 4,wherein the double bond is unsubstituted a substituted by at least one radical R,which process comprises subjecting a compound of the formula (I) ##STR8##in whichR, R.sup.1 and n are each as defined above, to a ring closure metathesis reaction in the presence of a noble metal catalyst.