نتایج جستجو برای: indolizidine
تعداد نتایج: 138 فیلتر نتایج به سال:
A homo-chiral synthesis of (7R,8aS)-octahydro-5,5-dimethylindolizin-7-amine 8 and (7S, 8aS)-octahydro-5,5-dimethylindolizin-7-ol 9, amine building blocks which have found applications within the pharmaceutical industry, is presented. The approach uses a Novozym 435-mediated kinetic resolution of racemic octahydroindolizine (indolizidine) alcohol 13 as a key step (up to 100 g scale).
Asymmetric syntheses of both 1-deoxy-6,8a-di-epi-castanospermine and 1-deoxy-6-epi-castanospermine, polyhydroxylated indolizidine alkaloids that act as selective glycosidase inhibitors, have been accomplished in seven steps. The key feature of our unique syntheses includes the stereoselective introduction of the C-3 and C-4 hydroxyl groups utilizing the aza-Claisen rearrangement-induced ring ex...
GC-MS analysis of single-skins of ten Melanophryniscus rubriventris toads (five collections of two toads each) captured during their breeding season in NW Argentina has revealed a total of 127 alkaloids of which 56 had not been previously detected in any frog or toad. Included among these new alkaloids are 23 new diastereomers of previously reported alkaloids. What is particularly distinguishin...
Indolizidine and quinolizidine derivatives are readily assembled from proline or pipecolic acid and γ-nitroaldehydes by means of a decarboxylative annulation process. These reactions are promoted by simple acetic acid and involve azomethine ylides as reactive intermediates. The method was applied to the synthesis of an epiquinamide analog.
Closing in on azacines: We have developed a new six step approach for the rapid and enantioselective synthesis of indolizidine, pyrrolo[1,2-a]azepine, and pyrrolo[1,2-a]azocine azabicyclic systems and their respective lactam congeners, which are found in a host of natural products as well as pharmaceutical preparations. This protocol enables a concise enantioselective total synthesis of (+)-gra...
A new indolizidine alkaloid, named Δ¹,⁶-juliprosopine (1), together with previously known indolizidine analogs (2- 6), was isolated from the leaves of Prosopis glandulosa var. glandulosa, collected from Nevada, USA; while two other known indolizidines, juliprosopine (6) and juliprosine (7), were isolated from P. glandulosa leaves collected in Texas, USA. The structures of compound 1 and 7 were ...
The synthesis, conformational study and inhibitory properties of diverse indolizidine and quinolizidine iminocyclitols are described. The compounds were chemo-enzymatically synthesized by two-step aldol addition and reductive amination reactions. The aldol addition of dihydroxyacetone phosphate (DHAP) to N-Cbz-piperidine carbaldehyde derivatives catalyzed by L-rhamnulose 1-phosphate aldolase fr...
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