Synthesis of oligosubstituted bullvalones: shapeshifting molecules under basic conditions.
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.
Lippert
Alex R
AR
Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106-9510, USA.
Kaeobamrung
Juthanat
J
Bode
Jeffrey W
JW