Patent ID: 6025519
Filing Date: 2000-02-15
Classification: C07C

Abstract:
Process for preparing cyclobutane- 1,2-dicarboxylic esters of the formula: ##STR9## in which R.sup.1 is a C.sub.1-8 -alkyl groups, an optionally substitued mono- or bicyclic cycloaliphatic group having 3 to 10 ring carbon atoms, an optionally substituted aryl or arylalkyl group or an optionally substituted tetrahydrofuryl or tetrahydropyranyl group and R.sup.2 is either C.sub.1-4 -alkyl or both radicals R.sup.2 together form a group of the general formula --(CH.sub.2).sub.n -- where n is an integer from 2 to 4, comprising reacting a dicarboxylic ester of the formula: ##STR10## in which R.sup.1 is as defined above, with a ketene acetal of the formula: ##STR11## in which R.sup.2 is as defined above, in the presence of a Lewis acid, and a sterically hindered base.