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Synthesis of oligosubstituted bullvalones: shapeshifting molecules under basic conditions
Alex R Lippert1, Juthanat Kaeobamrung, Jeffrey W Bode
1Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106-9510, USA.
Abstract:
Oligosubstituted bullvalones were synthesized in eight steps from 2,6-cycloheptadienone via a unique Lewis acid catalyzed intramolecular cyclopropanation of a stabilized sulfur ylide, leading directly to the tetracyclic cage structure. Upon exposure to base, the substituted bullvalones tautomerized to a hydroxybullvalene, which underwent dynamic interconversion into numerous, structurally distinct bullvalones. This system represents a "self-contained" dynamic combinatorial library in which the dynamic nature can be modulated by external reagents.
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