The invention provides a process for preparing a compound of the formula: ##STR1## or a base salt thereof, wherein R.sup.2 is hydrogen or C.sub.1 -C.sub.6 alkyl optionally substituted by up to 3 substituents each independently selected from the group consisting of C.sub.1 -C.sub.6 alkoxy and C.sub.1 -C.sub.6 alkoxy(C.sub.1 -C.sub.6 alkoxy)-; and R.sup.3 is C.sub.1 -C.sub.6 alkyl or benzyl, said benzyl group being optionally ring-substituted by up to 2 nitro or C.sub.1 -C.sub.4 alkoxy substituents comprising reacting a compound of the formula: ##STR2## wherein R.sup.1 is C.sub.1 -C.sub.4 alkyl, phenyl or benzyl or C.sub.1 -C.sub.4 alkoxy; and R.sup.2 and R.sup.3 are as previously defined for a compound of the formula (I), with hydrogen peroxide or a source of peroxide ions: said process being optionally followed by conversion of the compound of the formula (I) to a base salt thereof. The present invention also relates to novel compounds of the formula (II).
THE SYNTHESIS OF<i>GEM</i>-CYCLOPENTYL SUBSTITUTED GLUTARATES VIA THE OXIDATIVE RING CONTRACTION OF 2-ACETYLCYCLOHEXANONES
作者:Stephen Challenger、Andrew Derrick、Terry V. Silk
DOI:10.1081/scc-120012979
日期:2002.1
ABSTRACT A two step synthesis of differentially protected gem-cyclopentyl glutarates has been developed from 2-acetylcyclohexanone and acrylates. The key step involves an oxidative ringcontraction reaction with hydrogen peroxide. The methodology has been used to prepare intermediates used in the preparation of the atriopeptidase inhibitor candoxatril.