Asymmetric Total Syntheses of (−)-Hedycoropyrans A and B

详细信息    查看全文

• 作者：Zhilong Li ; Rongbiao Tong
• 刊名：Journal of Organic Chemistry
• 出版年：2017
• 出版时间：January 20, 2017
• 年：2017
• 卷：82
• 期：2
• 页码：1127-1135
• 全文大小：494K
• ISSN：1520-6904

文摘

The first and asymmetric total synthesis of (−)-hedycoropyrans A (1) was accomplished in 18 steps with 5.4% overall yield. The key features of our strategy include (1) construction of the unusual trans-2-aryl-6-alkyl tetrahydropyran core via Achmatowicz rearrangement, Zn-mediated reductive deoxygenation, and Heck–Matsuda coupling reaction, and (2) installation of 3,4-anti-dihydroxy from the corresponding 3,4-syn-dihydroxy THP through chemo- and regioselective IBX oxidation and Evans–Saksena reduction. In addition, C2 epimerization of (−)-hedycoropyan A (1) under the acidic condition furnished (−)-hedycoropyan B (2) with 71% yield. This finding might suggest the biogenetic origin of hedycoropyran B.