Total synthesis of streptonigrone.

A total synthesis of streptonigrone, 1, is described, which incorporates a one-step synthesis of substituted pyridones devised in our laboratory. Other aspects of the synthesis that differentiate the present approach from previous ones are the use of a Conrad-Limpach reaction, rather than the customary Friedländer methodology, to assemble the quinoline segment of 1, and the implementation of an anionic sequence for the functionalization of a key pyridone intermediate.