869369-08-4Relevant academic research and scientific papers
Divergent enantioselective synthesis of (-)-galanthamine and (-)-morphine
Trost, Barry M.,Tang, Weiping,Toste, F. Dean
, p. 14785 - 14803 (2007/10/03)
An efficient divergent synthetic strategy for the synthesis of the opiate and amaryllidaceae alkaloids emerges by employing a Pd-catalyzed asymmetric allylic alkylation (AAA) to set the stereochemistry. Three generations of syntheses of galanthamine are discussed in detail with particular focus on the scope of the palladium-catalyzed AAA reactions and intramolecular Heck reactions. The pivotal tricyclic intermediate is available in six steps from 2-bromovanillin and the monoester of methyl 6-hydroxycyclohexene-1-carboxylate. This intermediate requires only two steps to convert to (-)-galanthamine. Using a Heck vinylation, we found that the fourth ring of codeine/morphine could be formed. The final ring formation involves a novel visible light-promoted hydroamination. Thus, six steps are required to convert the pivotal tricyclic intermediate into codeine, which has been demethylated in high yield to morphine.
Development of aliphatic alcohols as nucleophiles for palladium-catalyzed DYKAT reactions: Total synthesis of (+)-hippospongic acid A
Trost, Barry M.,Machacek, Michelle R.,Tsui, Hong C.
, p. 7014 - 7024 (2007/10/03)
The ability to use aliphatic alcohols as competent nucleophiles in the palladium-catalyzed dynamic kinetic asymmetric transformation of Baylis-Hillman adducts is explored. High yield and enantioselectivity is obtained for both the kinetic transformation a
