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

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• 作者：Virginia M. Mastranzo^a ; ^{mastran@unam.mx} ; José ; Luis Olivares Romero^a ; Francisco Yuste^a ; Benjamí ; n Ortiz^a ; Rubé ; n Sá ; nchez-Obregó ; n^a ; José ; L. Garcí ; a Ruano^b
• 关键词：Tetrahydroprotoberberines ; Tetrahydropalmatine ; Canadine ; Pictet&ndash ; Spengler cyclization ; Asymmetric synthesis ; Sulfoxides
• 刊名：Tetrahedron
• 出版年：2012
• 出版时间：28 January, 2012
• 年：2012
• 卷：68
• 期：4
• 页码：1266-1271
• 全文大小：292 K

文摘

(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.