Porco and Zhu. Org. Lett., 2006, ASAP. DOI: 10.1021/ol062233m.
This concise synthesis of various members of the Mitorubin family by John Porco might be less controversial than my last post on his work, but it’s no less impressive. The centerpiece (for me at least) is a pair of copper-mediated transformations, appending the second ring and completing the core structure:
In the first reaction, the Cu(III)-spartine complex is used stoichiometrically, but to my eye doesn’t look too expensive… the methodology is discussed in this JACS from last year. The crude product from this reaction was then submitted to a Cu(I) catalysed cycloisomerisation, and acheived a 58% yield over the pair of steps – none too shoddy considering the complexity of the transformation.
BTW, props to Dr. Luke for pointing this one out to me…