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Enantioselective Total Synthesis and Absolute Configuration Assignment of (+)-Toxicodenane A
Xu-Long Qin1,2, Guo-Jie Wu1,3, Fu-She Han1,2
1Key Lab of Synthetic Rubber, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, Jilin 130022, China.
Abstract:
We present the first enantioselective total synthesis and absolute configuration assignment of (+)-toxicodenane A via a nine-step sequence from the readily available material. The synthesis features a desymmetric enantioselective reduction of 2,2-disubstituted 1,3-cyclohexanedione for the synthesis of a chiral 2,2-disubstituted 3-hydroxy cyclohexanone building block, a highly diastereoselective Grignard reaction for the incorporation of an allyl group, and a Lewis acid-mediated intramolecular transacetalation and Prins cascade reaction for the construction of oxa-bridged bicyclic rings.
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