| abstract |
In the process for preparing an organic compound of the formula n n A' -- X n n in which n X is an amino group, a hydroxyl group or a carboxyl group, and n A' is the remainder of the molecule, from an organic compound of the formula n n A -- X n n in which n A is the remainder of the molecule which can undergo reaction to form A', by converting A -- X into a compound of the formula n n A -- Z -- COOR n n in which n Z is --NH--, --O-- or a direct C--C bond, and n R is a radical of the formula ##STR1## IN WHICH Y is a direct C--C single bond, the --CH═CH-- group or an arylene group, n R 1 to R 4 each independently is hydrogen, halogen or an alkyl, aryl, aralkyl, alkoxycarbonyl, alkylaminocarbonyl, arylaminocarbonyl or cycloalkylaminocarbonyl radical, or n R 1 + r 2 and R 3 + R 4 each independently completes a 5- or 6-membered carbocyclic ring, or n R 1 and R 3 conjointly with the grouping --C--Y--C-- forms a carbocyclic ring with 5 or 6 carbon atoms, and Hal is halogen, n Thereby to protect X, then converting A -- Z -- COOR into a compound of the formula n n A' -- Z -- COOR n n and then treating the compound A' -- Z -- COOR to restore the group X, the improvement which comprises effecting the treatment of the compound A' -- Z -- COOR with an alkali metal compound of a complex of monovalent cobalt. The process is applicable particularly to aminocarboxylic acids including intermediates from various stages of the synthesis of penicillins and cephalosporins. |