Synthetic bacteriochlorins are of interest for fundamental studies in photochemistry because of their strong absorption in the near-infrared spectral region and close similarity with natural bacteriochlorophylls. A de novo route to 5-methoxybacteriochlorins entails self- condensation of a dihydrodipyrrin–acetal, which in turn is prepared from a 2-(2-nitroethyl) pyrrole species and an α, β-unsaturated ketone–acetal (eg, 1, 1-dimethoxy-4-methylpent- ...
