5703-23-1Relevant academic research and scientific papers
Total Synthesis of the Ortho-Hydroxylated Protoberberines (S)-Govaniadine, (S)-Caseamine, and (S)-Clarkeanidine via a Solvent-Directed Pictet-Spengler Reaction
Horst, Brendan,Wanner, Martin J.,J?rgensen, Steen Ingemann,Hiemstra, Henk,Van Maarseveen, Jan H.
, p. 15110 - 15117 (2018)
The common para regioselectivity in Pictet-Spengler reactions with dopamine derivatives is redirected to the ortho position by a simple change of solvents. In combination with a chiral auxiliary on nitrogen, this ortho-selective Pictet-Spengler produced the 1-benzyltetrahydroisoquinoline alkaloids (S)-crassifoline and (S)-norcrassifoline and the bioactive 1,2-dioxygenated tetrahydroprotoberberine alkaloids (S)-govaniadine, (S)-caseamine, and (S)-clarkeanidine with high enantiopurity. Ortho/para ratios up to 89:19 and diastereomeric ratios up to 85:15 were obtained during formation of the B-ring. The general applicability of this solvent-directed regioselectivity was demonstrated with a second Pictet-Spengler reaction as required for C-ring formation of caseamine (o/p = 14:86 in trifluoroethanol) and clarkeanidine (o/p = 86:14 in toluene).
NOVEL BICYCLIC AND TRICYCLIC PYRROLIDINE DERIVATIVES AS GNRH ANTAGONISTS
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, (2008/06/13)
Bicyclic and tricyclic pyrrolidine derivatives are disclosed that are useful as antagonists of the GnRH receptor. Methods for using the novel compounds to treat GnRH-related disorders are also provided, as are pharmaceutical compositions and novel synthetic methods.
