Abstract
Rational syntheses of the dihydro [(1d), (1e)] and monohydrated [(1b), (1c)] derivatives of protoporphyrin IX dimethyl ester have been completed. It has also been shown that the latter isomers [(1b), (1c)] can be obtained either from haematoporphyrin IX dimethyl ester (1a) by partial dehydration, or from diacetyldeuteroporphyrin IX dimethyl ester (1f) by partial reduction followed by dehydration and reduction.