The [4+4] photodimerization of 2-pyridones is as efficient method for preparing cyclooctadienes strategically functionalized for synthetic challenges such as taxol and the fusicoccanes. This single-step method for preparing complex structure from simple aromatic precursors proceeds with high region- and stereochemical control, but has not been exploited synthetically. Our studies of a previously untested intramolecular version of this reaction has laid the groundwork for applications to total synthesis. Two intramolecular approaches to taxol, and a synthesis of the complex fusicoccane are proposed. A preliminary study has demonstrated a selective intermolecular reaction of 4-alkoxy-2-pyridone with 2-pyridone, predicated on the inability to undergo [4+4] photodimerization. This new approach to control of the [4+4] reaction, in the absence of a tether, allows for other important targets to be addressed. Synthesis of the antibiotic pentalenolactone and an approach to taxol are proposed.
| Sieburth, S M; McGee Jr, K F; Zhang, F et al. (2000) Photoreactivity of 2-pyridones with furan, benzene, and naphthalene. Inter- and intramolecular photocycloadditions. J Org Chem 65:1972-7 |
| Lee, Y G; McGee Jr, K F; Chen, J et al. (2000) A [4 + 4] 2-pyridone approach to taxol. 3. Stereocontrol during elaboration of the cyclooctane. J Org Chem 65:6676-81 |
| Sieburth, S M; McGee Jr, K F (1999) Solvent-dependent stereoselectivity of bis-2-pyridone [4 + 4] photocycloaddition is due to H-bonded dimers. Org Lett 1:1775-7 |
