Key words
Stille reaction - Diels-Alder reaction - acid-catalyzed rearrangement
Significance
Significance
<P>(+)-Hexacyclinol is a metabolite isolated from Panus rudis strain HKI 0254 in 2002. The structure of this natural product has been the cause
of recent controversy [Chem. Eng. News 2006, 84
(
31), 11]. A synthesis of the proposed structure (J. La Clair Angew. Chem. Int. Ed. 2006, 45, 2769-2773) has recently been revised on the basis of calculated 13C NMR shifts (S. D. Rychnovsky Org. Lett. 2006, 8, 2895-2898). This work substantiates the revised structure and relates to a recent
biomimetic synthesis of (+)-panepophenanthrin by Porco and co-workers (Angew. Chem. Int. Ed. 2003, 42, 3913-3917) that amply displays the virtues of biomimetic strategy in natural product
synthesis.</P>
Comment
Comment
<P>Stille coupling of bromide B and vinyl stannane C gave D that, upon silyl cleavage, underwent Diels-Alder dimerization via exo transition state E to afford F. Subsequent treatment with K10 clay induced SN2′ substitution of the allylmethoxy group by the proximal Re face hydroxyl group giving the target.</P>
Reviews
Reviews
<P>
The Stille Reaction, V. Farina, V. Krishnamurthy, W. J. Scott Org. React (N.Y.) 1997, 50, 1-652. Clay and Clay-Supported Reagents in Organic Synthesis, R. S. Varma Tetrahedron 2002, 58, 1235-1255.</P>