Totally Synthetic by Paul H. Docherty, 24 October 2006

Total Synthesis of Mitorubrin

Porco

J. Zhu, J. A. Porco, Jr., Org. Lett. 2006, 8, 5169-5171.

DOI: 10.1021/ol062233m

This concise synthesis of various members of the Mitorubrin family by John Porco might be less controversial than my last post on his work, but it’s no less impressive. The centerpiece is a pair of copper mediated transformations, appending the second ring and completing the core structure:

In the first reaction, the Cu(III)-sparteine complex is used stoichiometrically, but to my eye doesn’t look too expensive. The crude product from this reaction was then submitted to a Cu(I) catalysed cycloisomerisation, and achieved a 58% yield over the pair of steps - not bad considering the complexity of the transformation.