Photochemical Approach to the Synthesis of the Pyrrolobenzodiazepine Antibiotics

Article abstract of DOI:10.1021/jo00285a022

The total syntheses of the pyrrolo<1,4>benzodiazepine antitumor antibiotics prothracarcin and DC-81 were realized using, as a key step, the photochemical <2δ + 2?> ring expansion of the appropriately substituted N-pentenylphthalimide to afford the corresponding pyrrolobenzazepinedione.Conversion of the photoproduct into the antibiotic skeleton was effected by transformation of the benzylic ketone into a carbinolamine via a Curtius rearrangement sequence.