Methodology for the construction of quaternary carbon centers

An asymmetric synthesis of the fugu fish poison, (−)-tetrodotoxin, is described. The route to this extraordinary target employs a number of unique transformations, foremost of which are two stereospecific C−H bond functionalization reactions. Accordingly, Rh-catalyzed carbene and nitrene C−H insertions facilitate rapid entry to the cyclohexane core of the natural product and make possible the late-stage installation of the tetrasubstituted carbinolamine center.

A stereoselective synthesis of (-)-tetrodotoxin.

Anti-Inflammatory Activity of Sesquiterpene Lactones and Related Compounds

b. Ring Closures of the Two-Carbon Bridge 42 c. Ring Closures of the One-Carbon Bridge 44 9. Free Radical-based Methods 44 a. Reductive Methods 44 b. Oxidative Methods 47 10. Organometallic-Based Methods 48 a. Iron Carbonyl Chemistry 48 b. Palladium Chemistry 49 11. Miscellaneous Methods 50 a. Wittig Olefination 50 b. Photochemical Rearrangements 51 c. Prins Reaction 51 IV. Cycloadditions and Other Electrocyclizations 51 1. [4+2] Cycloadditions 51 2. [5+2] Cycloadditions 52 3. [4+3] Cycloadditions 53 4. [3+2] Cycloadditions 54 5. [2+2+2] Cycloadditions 54 6. Ene-Type Cyclizations 54 7. Sigmatropic Rearrangements 55 V. Ring Expansion of Bicyclo[2.2.1]heptanes 55 VI. Rearrangement of Polycyclic Intermediates 58 1. Isomerization of Bicyclo[2.2.2]octanes 58 2. From Cyclopropane-Containing Intermediates 60 3. From Cyclobutane-Containing Intermediates 61 4. From Bridged Bicyclononane Precursors 62 VII. Reactivity 63 1. Fragmentations Leading to Nonbridged Carbocycles 63

Gary M. Ksander

Papers

A method for the synthesis of unsaturated carbonyl compounds

Stereospecific total synthesis of aphidicolin

A new method for the synthesis of vinyl ketones

Stereospecific total synthesis of aphidicolin