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Solid-phase Synthesis of [4.4] Spirocyclic Oximes
Published on: February 6, 2019
Total synthesis of (+/-)-stemodinone via an efficient ring-exchange strategy
T Tanaka1, K Murakami, A Kanda
1Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. t-tanaka@phs.osaka-u.ac.jp
Abstract:
A total synthesis of (+/-)-stemodinone, a tetracyclic stemodane diterpene, from the known tricyclic methyl olefin 11 is described. The key steps involve an efficient ring-exchange reaction and palladium(0)-catalyzed lactone migration. The ring-exchange strategy for controlling the stereochemistry was based on an initial Diels-Alder reaction to form a new ring followed by cleavage of the original ring. Cleavage of the original ring of the Diels-Alder adduct 9 was achieved by an initial regio- and chemoselective Baeyer-Villiger oxidation followed by the Pd(0)-catalyzed lactone-migration reaction reported by us.
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