503433-76-9Relevant articles and documents
The first total synthesis of xenitorins B and C: Assignment of absolute configuration
Chang, Wen-Sheng,Shia, Kak-Shan,Liu, Hsing-Jang,Wei Ly, Tai
, p. 3751 - 3753 (2008/09/18)
The first total synthesis of xenitorins B(1) and C(2) in natural form, which serves to confirm the structural assignments, establish the absolute stereochemistry and provide an easy access to the interesting marine sesquiterpenes was analyzed. The synthetic design calls for the use of optically active βpinene(3) both as the the starting substrate and source of chirality and its derivative 4 to facilitate the construction of the core system via a Diels-Alder reaction. This is followed by an acid catalyzed fragmentation process after suitable modifications. Formylation of (+)-7 followed by treatment of the resulting a-hydroxymethylene ketone with hydroxykamine gave rise to isoxazole(-)-9. The identity of the synthetic compounds and the corresponding natural products was established by direct comparison of their H nmr spectra. Result shows that B (-)1 and C(-)2 has been achieved and served to establish the absolute configuration of these structurally interesting natural products.
Synthesis of chiral thienylpyridines from naturally occurring monoterpenes: Useful ligands for cyclometallated complexes
Gianini, Michel,Von Zelewsky, Alex
, p. 702 - 706 (2007/10/03)
On treatment with ammonium acetate, α,β-unsaturated ketones or aldehydes can easily undergo condensation with acetylpyridinium salts (Krohnke reaction). Four 'thienylpyridine' ligands, derived from (-)-β-pinene, (+)-camphor, (+)-3-carene and (+)-2-carene, were prepared according to this method. The multistep syntheses to get (1R,5R)-3-methylenenopinone (5), (+)-3-methylenecamphor (10), (-)-3-caren-10-al (15) and (1S,6R)-7,7-dimethyl-3-methylenebicyclo[4.1.0]heptan-2-one (18) are also described.
