Tunable Cyclization Strategy for the Synthesis of Zizaene-, allo-Cedrane-, seco-Kaurane-, and seco-Atesane-Type Skeletons
journal contributionposted on 20.09.2017, 22:14 by Qianqian Yang, Wenjing Ma, Gaopeng Wang, Wenli Bao, Xiaoshu Dong, Xuefeng Liang, Lizhi Zhu, Chi-Sing Lee
A versatile Lewis acid-mediated cyclization strategy has been developed for selectively establishing zizaene-, allo-cedrane-, seco-kaurane-, and seco-atesane-type skeletons. The zizaene- and seco-atesane-type skeletons can be obtained in a cascade manner, which involves Diels–Alder reaction of cyclic enones with bis-silyloxy dienes and carbocyclization of yne–enolates through Lewis acid dependent 5- or 6-exo-dig modes. This cyclization strategy was also employed for the core synthesis of tashironin.