Synthesizing eight-membered rings has long been a challenging task. However, recent studies from the Ovaska lab have shown that tandem 6-exo-dig cyclization/Claisen rearrangement can be used for the practical preparation of a variety of cyclooctanoid systems. This sequence requires an appropriately substituted 5-hexyn-1-ol precursor, which is activated toward cyclization via an electron-withdrawing group on the triple bond. Following base-catalyzed cyclization, rearrangement occurs readily under microwave irradiation to generate the desired eight-membered ring.
This thesis explores the application of sequential 6-exo-dig cyclization/Claisen rearrangement to the synthesis of natural product and cyclooctanoid system, (+)-precapnelladiene, and in doing so, elaborates upon the scope of this unique methodology.
Iannaro, Victoria, "Synthetic pursuit of (+)-precapnelladiene via tandem 6-exo-dig cyclization/Claisen rearrangement" (2015). Chemistry Honors Papers. 16.
The views expressed in this paper are solely those of the author.