Organic Letters
Letter
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presented, which subsequently inspired a biomimetic synthesis
of two pseudocerosine pyridoacridine diastereomers that
possess NMR spectroscopic data consistent with the natural
product. Moreover, we have validated a biosynthetic proposal
for the formation of the E-ring in pyridoacridine alkaloids, and
pseudocerosine (including many of its intermediates) is a new
branch on the pyridoacridine family tree.8
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ASSOCIATED CONTENT
* Supporting Information
■
sı
́
Tetrahedron Lett. 2019, 60, 1437−1440. (e) Condie, A. G.; Gonzalez-
The Supporting Information is available free of charge at
́
Gomez, J. C.; Stephenson, C. R. J. J. Am. Chem. Soc. 2010, 132, 1464−
1465.
(14) We were unable to obtain crystals of 26a, 26b, 27a, and 27b
that were suitable for X-ray analysis. As a result, the relative
stereochemistry of each diastereomer could not be determined. The
relative relationships between the C−N bond of the C-13 aminal and
the S−O bond of the sulfoxide were used to designate the
diastereomers as syn and anti. The assignments in Scheme 4 could
be inverted (i.e., 26a and 27a could be anti; 26b and 27b could be
syn).
Experimental procedures and NMR spectra for all novel
Accession Codes
CCDC 1966507 contains the supplementary crystallographic
data for this paper. These data can be obtained free of charge
bridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: +44 1223 336033.
AUTHOR INFORMATION
Corresponding Author
■
Jonathan Sperry − School of Chemical Sciences, University of
Authors
Se Hun Kim − School of Chemical Sciences, University of
Auckland, Auckland 1010, New Zealand
̈
Tilo Sohnel − School of Chemical Sciences, University of
Auckland, Auckland 1010, New Zealand
Complete contact information is available at:
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We thank the Royal Society of New Zealand for a Rutherford
Discovery Fellowship (J.S.) and the University of Auckland for
a doctoral scholarship (S.H.K.).
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