1. For general reviews of rhodium-mediated C−H insertions, see: (a) Taber D. F.Comprehensive Organic Synthesis; Pattenden, G., Ed.; Pergamon Press: Oxford, 1991; Vol. 3, pp 1045−1062. (b) Doyle, M. P. InHomogeneous Transition Metal Catalysts in Organic Synthesis; Moser, W. R., Slocum, D. W., Eds.; ACS Advanced Chemistry Series, No. 230; American Chemical Society: Washington, D.C., 1992; Chapter 30. (c) Padwa, A.; Austin, D. J.Angew. Chem., Int. Ed. Engl.1994,33, 1797−1815. (d) Ye, T.; McKervey, M. A.Chem. Rev.1994,94, 1091−1160.
2. A general approach to the synthesis of C8-oxygenated guaianolides