Total Synthesis of Marine Sesquiterpene Quinones (+)-Cyclospongiaquinone-1 and (-)-Dehydrocyclospongiaquinone-1 with a Tetracyclic Benzo[a]xanthene Skeleton

详细信息    查看全文

• 作者：Yuki Takeda ; Koichi Narita and Tadashi Katoh
• 刊名：European Journal of Organic Chemistry
• 出版年：2017
• 出版时间：January 26, 2017
• 年：2017
• 卷：2017
• 期：4
• 页码：901-907
• 全文大小：1060K
• ISSN：1099-0690

文摘

Two marine sesquiterpene quinones, (+)-cyclospongiaquinone-1 and (–)-dehydrocyclospongiaquinone-1, were efficiently synthesized in 10 and 12 steps and overall yields of 33 and 24 %, respectively, from commercially available (+)-sclareolide. The synthetic strategy involves the following crucial steps: (i) assembly of the carbon skeleton by coupling the decalin segment to the aromatic moiety; (ii) one-step construction of the dihydropyran ring by acid-induced acetonide deprotection/ether cyclization of an olefinic decalin intermediate that contains the aromatic moiety; (iii) formation of the p-benzoquinone moiety by oxidation of a p-methoxyphenolic derivative to produce (+)-cyclospongiaquinone-1; and (iv) oxidative dehydrogenation at the C-12–C-12a bond of a tetracyclic intermediate to obtain (–)-dehydrocyclospongiaquinone-1.