I. S. Young, Matthew W. Haley, Annie Tam
Oct 16, 2015
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Influential Citations
7
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Journal
Organic Process Research & Development
Abstract
A scalable synthesis of (R,R)-2,6-dimethyldihydro-2H-pyran-4(3H)-one is reported. Key to this strategy is the Ti(OiPr)4-catalyzed Kulinkovich cyclopropanation of silyl protected (R)-ethyl 3-hydroxybutanoate, and subsequent oxidative fragmentation of the cyclopropanol. The resulting vinyl ketone intermediate was then subjected to oxidative Heck cyclization to form the enone substrate required for conjugate addition. A diastereoselective copper-catalyzed Grignard addition procedure was implemented to install the requisite methyl group, with the inclusion of 1,3-bis(diphenylphosphino)propane and trimethylsilyl chloride greatly increasing the robustness of this process.