Stemonamine (1) was isolated from the roots of Stemona japonica Miq. as a member of the Stemona alkaloid family. Although the racemic total syntheses of 1 or stemonamide (3) have been reported by three groups, its enantioselective synthesis has not been reported so far. In this presentation, the total synthesis of 1 using the reactions that we have developed, such as the ynolate-initiated tandem reaction and the intramolecular acylation, is described. Our synthesis commenced with condensation of the known optically active carboxylic acid 16 and the lactone 17 to give the iodide 15 in 4 steps. The intramolecular acylation of 15 using ^tBuLi afforded the 7-member ring 22 in high yield as the first key reaction. The TBS protection of 22 and the oxidative cleavage of the terminal alkene, followed by esterification, provided the methyl ester 14c. As the second key step, the tandem [2+2]cycloaddition-Dieckmann condensation using ynolate anion 6 and 14c was performed to successfully provide the enone 28c in high yield. After transformation of 28c to the diacetate 31, the acetoxy group on the C-ring was removed via the SmI_2-mediated reduction in good yield to afford the Tu's synthetic intermediate 33. At last, the total synthesis of 1 was achieved via the Tu's method. The spectroscopic data of our synthetic 1 were in good agreement with those recorded in the literature. [chemical formula]
