Journal of the American Chemical Society
Communication
To demonstrate the utility of the cylopentanone products,
a Baeyer−Villager oxidation and a Beckman rearrangement
were carried out. In both cases, retention of stereochemistry was
observed and lactone 8 and lactam 9 products were formed in
good yields (Scheme 3).
Scheme 2. Control Experiments
In conclusion, we have developed a methodology for the
enantioselective synthesis of 3,4-disubstituted cyclopentanones.
The protocol allows for the dimerization of aryl enals18 to form
C-2 symmetric cyclopentanones. Further, a cross reaction has
been developed to synthesize nonsymmetric 3,4-disubstituted
cyclopentanones. The proposed reaction mechanism invokes
radical intermediates. Furthering the substrate scope and
investigating new modes of reactivity enabled by these inter-
mediates is the subject of ongoing investigations.
ASSOCIATED CONTENT
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S
* Supporting Information
The Supporting Information is available free of charge on the
that would deliver unsymmetrical adducts. All attempts at using
other electron-deficient alkenes (such as nitroalkenes, enoates,
enones) met with failure; the reaction appears to require an enal
on both sides. As a partial solution, we found that biasing the
reaction with an excess of one of the enals delivers the cross
product in good yields. Best results are achieved when the more
electron-rich (more reactive) enal is used in excess. In these
reactions, the dimer of the more reactive enal is always formed,
but the dimer of the limiting enal is observed in only trace
amounts (Table 3).
Experimental procedures and compound characterization
AUTHOR INFORMATION
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Corresponding Author
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
ab
,
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Table 3. Cross-Reaction
We thank NIGMS for generous support (GM72586) and Daniel
DiRocco (Merck Research Laboratories) for a generous gift of
aminoindanol. We thank Daniel Reuss (CSU) for help with
assaying CO2 levels. Funding by NIGMS (GM72586).
REFERENCES
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b
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Scheme 3. Derivatization
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