Cyclooctane annulation

An illustrative example of the potency of the second-generation Ru catalyst C is found in Paquette s highly efficient total synthesis of the natural products teubrevin G (122) and teubrevin H (123), which feature a cyclooctane core fused and spiroannulated to smaller oxygen-containing rings [76]. In the retrosyn-thetic analysis, the viability of an RCM step for annulation of a cyclooctenone ring to the furan played a central role. 

Cyclopentadienylcobalt(l) complexes react with 1,2,3-selenadiazoles 16 annulated with unsaturated cyclooctane rings to afford fluxional complexes 23 <1987JOMC39, 19890M800>, as illustrated in Equation (3). Reaction of these... 

Annulated cyclooctane derivatives such as 13 have been prepared from Cope substrates of type 12 b38. Rearrangement of alcohol 14 has been used as the key step in the stereoselective synthesis of ( )-pleuromutilinl095. 

Three methods have been developed to fuse a cyclooctane ring onto a pre-existing cyclic system. These annulations have again been organized according to our conventions for describing intramolecular allylsilane additions to conjugated dienones. 

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