Cover Picture: A Short Synthesis of Clionamine D (Chin. J. Chem. 11/2015) (page 1221)
Xiang Hao, Jingjing Wu, Hailong Tian, Yong Shi, Jingrong Lin and Weisheng Tian
Article first published online: 17 NOV 2015 | DOI: 10.1002/cjoc.201590025
The cover picture shows a short and efficient synthesis of clionamine D. Steroidal α-methylene-γ-lactones are versatile intermediates for synthesizing related natural products such as clionamines A–D, a family of marine natural alkaloids with potent autophagy bioactivities and unprecedented chemical structures. Employing single oxygen to break the C22-C23 double bond via a [2+2]/retro-[2+2] process, Shi and Tian et al. have developed a scalable, four-step procedure to prepare α-methylene-γ-lactone directly from steroidal sapogenin–needn't prepare dinorcholanic lactone first. A synthesis of clionamine D was therefore achieved in eight steps with an overall yield of 31%. More details are discussed in the article by Tian et al. on page 1235–1238.