109685-13-4Relevant articles and documents
Total synthesis of celastrol, development of a platform to access celastroid natural products
Camelio, Andrew M.,Johnson, Trevor C.,Siegel, Dionicio
, p. 11864 - 11867 (2015)
Celastroid natural products, triterpenes, have been and continue to be investigated in clinical trials. Celastrol, and for that matter any member of the celastroid family, was prepared for the first time through chemical synthesis starting from 2,3-dimethylbutadiene. A triene cyclization precursor generated in 12 steps underwent a nonbiomimetic polyene cyclization mediated by ferric chloride to generate the generic celastroid pentacyclic core. In the cyclization, engagement of a tetrasubstituted olefin formed adjacent all carbon quaternary centers stereospecifically. With access to the carbocyclic core of the family of natural products, wilforic acid and wilforol A were prepared en route to racemic celastrol.
An interesting issue of Diels-Alder selectivity discovered en route to 11-O-debenzoyltashironin
Cook, Silas P.,Danishefsky, Samuel J.
, p. 5693 - 5695 (2007/10/03)
(Diagram presented) The hypervalent iodine-mediated oxidative dearomatization/Diels-Alder cascade was examined in the context of the natural product 11-O-debenzoyltashironin. Interestingly, the regioselectivity of the Diels-Alder reaction can be completely switched by changing the dienophile. Trapping of allyl alcohols during the oxidative dearomatization gives rise to the five-membered acetal, while trapping of allenyl alcohols results in the six-membered acetal.
En route to the total synthesis of tashironin: On the exercise of stereochemical control by a methyl group in mediating remote cyclization reactions
Cook, Silas P.,Christoph, Gaul,Danishefsky, Samuel J.
, p. 843 - 847 (2007/10/03)
The synthesis of the [2.2.2]-bicyclic core (23) of the neurotrophic factor 11-O-debenzoyltashironin (1) has been achieved by an oxidative dearomatization-transannular Diels-Alder cascade. We have shown that the reaction sequence is also valuable for the efficient construction of related, complex [2.2.2]-bicyclic compounds (vide infra).
