Enantioselective Synthesis of (+)-Peganumine A

A gram-scale enantioselective total synthesis of (+)-peganumine A was accomplished in 7 steps from commercially available 6-methoxytryptamine. Key steps included (a) a Liebeskind−Srogl cross-coupling; (b) a one-pot construction of the tetracyclic skeleton from an ω-isocyano-γ-oxo-aldehyde via a sequence of an unprecedented C−C bond forming lactamization and a transannular condensation; (c) a one-pot organocatalytic process merging two achiral building blocks into an octacyclic structure via a sequence of enantioselective Pictet−Spengler reaction followed by a transannular cyclization. This last reaction created two spirocycles and a 2,7-diazabicyclo[2.2.1]heptan-3-one unit with excellent control of both the absolute and relative stereochemistry of the two newly created quaternary stereocenters.


Published in:
Journal of the American Chemical Society, 138, 35, 11148-11151
Year:
2016
Publisher:
Washington, American Chemical Society
ISSN:
1520-5126
Laboratories:




 Record created 2016-09-14, last modified 2018-03-17


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