A concise total synthesis of unprecedented tetranorsesquiterpenoids applanatumol Z5

• Published in: Tetrahedron letters 2020-11, Vol.61 (47), p.152580, Article 152580
• Main Authors: Wang, Kunkai, Tan, Xiangchuang, Xie, Zhixiang
• Format: Article
• Language: English
• Subjects: Applanatumol Z5; Diels-Alder reaction; Oxidative coupling; Selective carbonyl reduction; Two vicinal quaternary carbon stereocenters
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2020.152580

[Display omitted] •A concise total synthesis of tetranorsesquiterpenoids applanatumol Z5 was achieved.•An unexpected intramolecular dithiolane with alcohol oxidative coupling.•A regioselective Diels-Alder reaction constructed the 6/5/5 tricyclic scaffold.•Diels-Alder reaction constructed two vicinal quaternary carbon stereocenters. A concise total synthesis of tetranorsesquiterpenoids applanatumol Z5 (3), possessing unique 6/5/5 ring system was disclosed with 7-step in 5-pot from commercially available starting materials. The key elements of the synthesis included an unexpected intramolecular dithiolane with alcohol oxidative coupling/deprotection sequence to create the unsaturated lactone as dienophile and a regioselective Diels-Alder reaction to assemble the 6/5/5 tricyclic scaffold including two vicinal quaternary carbon stereocenters. Late stage the diastereo- and regioselective carbonyl reduction led to achieve the total synthesis of (±) applanatumol Z5 (3).