A novel total synthesis of ( /-)shikonin

作者:Xu, De Feng; Guo, Xiao Juan; Xu, Zhao Hui; Li, Shao Shun*
来源:Chinese Chemical Letters, 2006, 17(7): 871-873.

摘要

A novel total synthesis of (+/-)shikonin 1 was presented. The key intermediate 6 was achieved by the formylation of 1,8:4,5-bis(methylenedioxy)naphthalene 5 with N-methylformanilide in good yield. It was first reported that the addition of prenyllithium to 2-formyl-1,8:4,5bismethylenedioxy naphthalene 6 gave 2-(1-hydroxy-4-methylpentyl) 1,8:4,5-bis(methylenedioxy) naphthalene 8 in 45% yield and 2-(1-hydroxy-2,2-dimethyl-3-butenyl)-1,8:4,5-bis(methylenedioxy)naphthalene 9 in 48% yield. After the electrooxide deprotection of 8, (+/-)shikonin 1 was prepared in high yield.