Process for preparing higher diesters of {alpha}, {omega}-dicarboxylic acids

Popisuje se zp sob v²roby .alfa.,.omega.-dikarboxylov²ch kyselin z cykloalifatick²ch keton s 8 a 20 leny kruhu a diester kyseliny uhli it v p° tomnosti siln z sadit ho prost°edku, p°i kter m se cykloalifatick² keton, 1 a 2,5n sobn mol rn mno stv diesteru kyseliny uhli it a 0,05 a 0,5 ekvivalentu lithia, sod ku nebo drasl ku, jako i jejich hydrid , amid nebo alkohol t p°iv d kontinu ln do reak n oblasti, ve kter doch z ke kondenzaci cykloalifatick ho ketonu s diesterem kyseliny uhli it na odpov daj c cyklick² esterenol t .beta.-ketokyseliny a Üt pen jeho kruhu uvoln n²m alkoholem za vzniku diesteru .alfa.,.omega.-dikarboxylov kyseliny, a ze kter se kontinu ln odtahuje reak n sm s.\ In the present invention there is described a process for preparing higher diesters of {alpha}, {omega}-dicarboxylic acids from cycloaliphatic ketones having 8 to 20 ring members and carbonic diesters in the presence of a strongly basic agent, which preparation process involves: continuously feeding a cycloaliphatic ketone having 8 to 20 ring members, 1 to 2.5 times molar amount of a carbonic acid diester and 0.05 to 0.5 equivalents per mole of lithium, sodium or potassium or anhydrides thereof into a reaction zone wherein condensation of the cycloaliphatic ketone with the carbonic diester to give a cyclic {beta}-keto acid ester enolate and ring-opening of the cyclic {beta}-keto acid ester enolate by an alcohol to give the {alpha}, {omega}-dicarboxylic diester take place in said reaction zone and continuously removing an amount of the resulting reaction mixture from the reaction zone in an amount sufficient to maintain a steady state level of reaction mixture in the reaction zone.