A novel and versatile method for the enantioselective syntheses of tropane alkaloids

作者：Mao ZhongYi; Huang SuYu; Gao LongHui; Wang AiE; Huang PeiQiang^*

来源：Science China Chemistry, 2014, 57(2): 252-264.

DOI：10.1007/s11426-013-4998-2

• synthetic methods
• tropane alkaloids
• cyclization
• activation
• amides

A full account of the novel and flexible approach to hydroxylated 8-azabicyclo[3,2,1]octan-3-ones and 9-azabicyclo[3,3,1] nonan-3-ones is presented. Using keto-lactams as the starting materials, this two-step method consists of silyl enol ether formation with TBDMSOTf, lactam activation with Tf2O/DTBMP, and halide-promoted cyclization. Radical dechlorination of the resulting 1-halotropan-3-ones led to the corresponding hydroxylated tropan-3-ones, which can be hydrogenated to yield 3 alpha,6 beta-dihydroxytropanes. Starting from optically active keto-lactams, the method has been applied to the enantioselective syntheses of (+)-(1S,3S,5R,65)-pervilleine C (6), (+)-(1S,3R,5S,6R)-valeroidine (3), (+)-(1S,3S,5R,6,9)-dibenzoyloxytropane (8), and (+)-(1S,3S,5R,6S)-merredissine (9).

• 出版日期2014-2
• 单位厦门大学