3¹-Racemically pure zinc 3¹-hydroxy-13¹-oxo-porphyrins (zinc methyl 17,18-dehydro-bacteriopheophorbides-d) as well as their 3¹-demethyl form were prepared by modifying chlorophyll-a through oxidation by 2,3-dichloro-5,6-dicyano-benzoquinone. From visible, circular dichroism and infrared spectral analyses, these synthetic pigments self-aggregated in 1%(vol/vol) tetrahydrofuran and cyclohexane to give large oligomers by an intermolecular bonding of 13-C=O⋯H–O(3¹)⋯Zn(central) and π–π interaction of the porphyrin chromophores. The supramolecular structures are similar to those of the corresponding chlorins and a core part of extramembranous light-harvesting antennas of photosynthetic green bacteria. The 17,18-dehydrogenation of a chlorin to porphyrin moiety did not disturb its self-aggregation, and the synthetic zinc porphyrins are good models for naturally occurring, self-aggregative bacteriochlorophylls.