Asymmetric synthesis of (S)-(-)-tetrahydropalmatine and (S)-(-)-canadine via a sulfinyl-directed Pictet-Spengler cyclization

作者：Mastranzo Virginia M^*; Olivares Romero Jose Luis; Yuste Francisco; Ortiz Benjamin; Sanchez Obregon Ruben; Garcia Ruano Jose L

来源：Tetrahedron, 2012, 68(4): 1266-1271.

DOI：10.1016/j.tet.2011.11.046

• Tetrahydroprotoberberines
• Tetrahydropalmatine
• Canadine
• Pictet-Spengler cyclization
• Asymmetric synthesis
• Sulfoxides

(S)-(-)-Tetrahydropalmatine 2 and (S)-(-)-canadine 4 were synthesized in three steps from (S)-6, in 33% and 34% overall yield, respectively. Thus, condensation of the (S)-(E)-sulfinylimines 10 and 11 with the carbanion derived from (S)-6 gave the tetrahydroisoquinolines 12 and 13, respectively, which upon TFA induced N-desulfinylation, and subsequent microwave assisted Pictet-Spengler cyclization effected both cyclization and C-desulfinylation producing (S)-(-)-tetrahydropalmatine 2 and (S)-(-)-canadine 4 in optically pure form.

• 出版日期2012-1-28