Exploiting the reversibility of olefin metathesis. Syntheses of macrocyclic trisubstituted alkenes and (R,R)-(-)-pyrenophorin.
[figure: see text] The formation of the trisubstituted cycloalkene 7 by RCM of diene 5 proceeds via the acyclic dimer 6, thus demonstrating the ready reversibility of olefin metathesis if catalyzed by "second generation" ruthenium carbene complexes such as 2-4. When applied to acrylate 11, these catalysts trigger a cyclooligomerization process that evolves with time and serves as key step en route to the lactide antibiotic (-)-pyrenophorin 8.
Fürstner
A
A
Max-Planck-Institut für Kohlenforschung, D-45470 Mülheim/Ruhr, Germany. fuerstner@mpi-muelheim.mpg.de
Thiel
O R
OR
Ackermann
L
L
D000475:Alkenes / Q000138:chemical synthesis*; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis*; D006844:Hydrocarbons, Cyclic / Q000138:chemical synthesis*; D007783:Lactones / Q000138:chemical synthesis*
D000475:Alkenes; D000900:Anti-Bacterial Agents; D006844:Hydrocarbons, Cyclic; D007783:Lactones; C013228:pyrenophorin