159.Total Synthesis of (+)-Cyclobutastellettolide B

Zhongchao Zhang, Sijia Chen, Fu Tang, Kai Guo, Xin-Ting Liang, Jun Huang,* and Zhen Yang*

J. Am. Chem. Soc. 2021, 143,(43), 18287–18293

A convenient enantioselective total synthesis of (+)-cyclobutastellettolide B via a strategy that involves a diastereoselective Johnson–Claisen rearrangement, a regioselective cyclopropoxytrimethylsilane ring-opening reaction, and a Norrish–Yang cyclization is described. The results of computational and experimental studies indicate that the regio- and stereoselectivity of the Norrish–Yang reaction are controlled by the C–H bond dissociation energy and restricted rotation of the C13–C14 bond.