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Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Poly-oxygenated tricyclobutabenzenes via repeated [2 + 2] cycloaddition of benzyne and ketene silyl acetal
Toshiyuki Hamura1, Yousuke Ibusuki, Hidehiro Uekusa
1Department of Chemistry, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8551, Japan.
Abstract:
Described herein is a synthesis of highly functionalized tricyclobutabenzenes, a class of molecules of structural and theoretical interest. The preparation is based on the repeated [2 + 2] cycloadditions of benzyne and ketene silyl acetals (KSAs), where two types of regioselectivity enable discrimination of the functionalities on the four-membered rings. By these steps, we were able to prepare poly-oxygenated octamethoxytricyclobutabenzene and its hydrolyzed tetra-oxo derivatives. Structural study on the latter compound showed the interesting properties related to the strained four-membered ring.
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