Total Synthesis Of Vinigrol
Vinigrol, an unusual diterpene, was isolated by Hashimoto and co-workers in 1987, from the fungal strain Virgaria nigra F-5408. Biological test of vinigrol has revealed a number of interesting properties, such as antihypertension and platelet aggregation inhibition. Vinigrol is also a tumor necrosis factor (TNF) antagonist. The promising biological activities, combined with its unique terpene structure have attracted significant attention from the synthetic community. Herein, a total synthesis of vinigrol is described. The synthesis demonstrates the power of oxidative dearomatization and intramolecular Diels-Alder cycloaddition to construct complex molecules. Additionally, a few new synthetic strategies and tactics were developed, such as selenium dioxide mediated olefin isomerization and oxidation, stereoselective installation of an isopropyl group and strategic applications and deprotection of trifluoroethyl ethers.