Organic Letters
Letter
treatment of 6j, 6k, and 6n with TfOH furnished zigzag
(armed-chair) shaped PAHs, such as the chrysenes 10j and 10k
and picene 10n, which have been demonstrated to display
semiconductor properties3d (Scheme 3). The products were
formed by an E1-type elimination reaction with the assistance
of the acid catalyst. The formation of the spirocyclic
intermediate 9 was prohibited by the steric repulsion of the
upper-rimmed naphthalene ring. A careful survey of the
reaction mixtures used in the reactions of 6d and 6r clarified
that trace amounts of the elimination products 10d and 10r,
respectively, were formed.
for Young Scientists (Y.N.). Dedicated to the memory of
Keiichiro Fukumoto, Emeritus Professor, Tohoku University,
who passed away on July 5, 2013.
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ASSOCIATED CONTENT
* Supporting Information
Skoric,
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I. Tetrahedron 2014, 70, 886−891.
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Experimental procedures, full characterization of new products,
X-ray data, and copies of NMR spectra. This material is
AUTHOR INFORMATION
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Corresponding Author
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
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This work was supported by a Grant-in-Aid for Scientific
Research, “Platform for Drug Design, Discovery and Develop-
ment” from MEXT, Japan, and by a JSPS Research Fellowship
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dx.doi.org/10.1021/ol403757e | Org. Lett. 2014, 16, 1008−1011