60384-53-4Relevant articles and documents
Total synthesis of (±)-galanthamine from GABA through regioselective aryne insertion
Venkatesh, Telugu,Mainkar, Prathama S.,Chandrasekhar, Srivari
, p. 2192 - 2198 (2019/02/27)
The total synthesis of (±)-galanthamine is achieved in ～5% overall yield using a key regioselective aryne insertion reaction into a GABA (γ-amino butyric acid) derivative. The strategy presented involves only two sub-critical temperature reactions and less than five chromatographic purifications to achieve the synthesis of galanthamine.
Stereoselective syntheses of galanthamine and its stereoisomers by complementary Luche and L-selectride reductions
Trinadhachari, Ganala Naga,Kamat, Anand Gopalkrishna,Raghu Babu, Korupolu,Sanasi, Paul Douglas,Prabahar, Koilpillai Joseph
, p. 117 - 124 (2014/02/14)
A diastereodivergent approach for the stereoselective syntheses of all four stereoisomers of galanthamine, (-)-galanthamine 1, (+)-galanthamine 2, (-)-epigalanthamine 3, and (+)-epigalanthamine 4, from (±)-narwedine 5 is reported. Thus (±)-narwedine 5 was resolved by dynamic kinetic resolution to obtain enantiomerically pure (-)-narwedine 6 and (+)-narwedine 7. Each enantiomerically pure isomer of narwedine was subjected to Luche and L-selectride reactions to obtain all four isomers of galanthamine. In these reactions, the (-)-galanthamine 1 and (+)-galanthamine 2 isomers were obtained with an enantiomeric purity of >99.5%, whereas (-)-epigalanthamine 3 and (+)-epigalanthamine 4 are obtained with a chiral purity of >97%. The axial hydride attack by the Luche reduction and the equatorial hydride attack by the L-selectride reduction on the cyclic enone system are explored in the stereoselective synthesis of the galanthamine isomers and thus it was demonstrated that the stereoselective synthesis involving the Luche and L-selectride reductions are complementary in yielding enantiomeric stereogenic centers from a prochiral carbonyl group on the cyclic enone system.
Commercial scale process of galanthamine hydrobromide involving Luche reduction: Galanthamine process involving regioselective 1,2-reduction of α,β-unsaturated ketone
Trinadhachari, Ganala Naga,Kamat, Anand Gopalkrishna,Prabahar, Koilpillai Joseph,Handa, Vijay Kumar,Srinu, Kukunuri Naga Venkata Satya,Babu, Korupolu Raghu,Sanasi, Paul Douglas
, p. 406 - 412 (2013/06/05)
Effect of lanthanide chloride in the Luche regioselective 1,2-reduction of 1-bromo-11-formyl-nornarwedine (5) was studied. Thus, 1-bromo-11-formyl- nornarwedine (5) is reduced with sodium borohydride in the presence of lanthanide chloride to yield 1-bromo-11-formyl-galanthamine isomers (6), which is a key intermediate for the commercial production of highly pure galanthamine hydrobromide (1), a modern drug against Alzheimer's disease.
