Treatment of N-cyanomethyl-6-hydroxy-1,2,3,4-tetrahydroisoquinolinium methiodide (1) with NaOMe in MeOH caused C1-N fission and simultaneous recyclization to give 8-hydroxy-5-methoxymethyl-1,2,3,4-tetrahydroisoquinoline (2). By using of the rearrangement synthesis of litebamine (4) was carried out.
A facile and efficientone-pot method for the synthesis of a tetrahydronaphtho[2,1-f]isoquinoline alkaloid by using domino Pictet–Spengler/Friedel–Crafts-type cyclization reactions has been reported. Litebamine, a naturally occurring compound, was prepared by using this proposed approach to exemplify its utility.
已经报道了一种利用多米诺Pictet-Spengler / Friedel-Crafts型环化反应合成四氢萘并[2,1- f ]异喹啉生物碱的简便有效的一锅法。通过使用这种提议的方法来证明其实用性,制备了一种天然存在的化合物立巴明。
A facile semisynthesis of litebamine, a novel phenanthrene alkaloid, from boldine via a biogenetical approach
Litebamine was semisynthesized from boldine via a biogenetical approach. Main reactions include Von Braun reaction, exhaustive benzylation and Hofmanndegradation in one pot, and the Mannich reaction.
First total syntheses of the 1,2,3,4-tetrahydronaphtho[2,1-f]isoquinolines annoretine and litebamine
作者:M.Carme Pampı́n、Juan C Estévez、Ramón J Estévez、Rafael Suau、Luis Castedo
DOI:10.1016/s0040-4020(03)01135-9
日期:2003.9
We describe here the first total synthesis of the two natural 1,2,3,4-tetrahydronaphtho[2,1-f]isoquinolines, annoretine and litebamine, from [2-(2-styrylphenyl)ethyl]methylcarbamic acid ethyl esters. The key steps were the Bischler-Napieralski cyclization to form the isoquinoline unit and photocyclization of the resulting 2-methyl-5-styryl-3,4-dihydro-2H-isoquinolin-1-ones to 2-methyl-3,4-dihydro-2H-naphtho[2,1-f]isoquinolin-1-ones. (C) 2003 Elsevier Ltd. All rights reserved.
Litebamine <i>N</i>-Homologues: Preparation and Anti-Acetylcholinesterase Activity
作者:Chi-Ming Chiou、Jaw-Jou Kang、Shoei-Sheng Lee
DOI:10.1021/np970298f
日期:1998.1.1
Litebamine N-homologues were easily prepared from laurolitsine, generally via three reaction steps (N-alkylation, solvolysis with 1 M NH4OAc under reflux, and the Mannich reaction) in more than 80% overall yield. Among the prepared compounds, N-propyl-, N-isobutyl-, and N-isopropylnorlitebamines exhibited moderate antiacetylcholinesterase activity (IC50 Ca 7.0 mu M), while the corresponding N-metho salt of N-propylnorlitebamine showed potent activity (IC50 2.70 mu M).
A novel ring cleavage and recyclization of N-cyanomethyl-1,2,3,4-tetrahydroisoquinolinium methiodides: A biomimetic synthesis of litebamine
Treatment of N-cyanomethyl-6-hydroxy-1,2,3,4-tetrahydroisoquinolinium methiodide (1) with NaOMe in MeOH caused C1-N fission and simultaneous recyclization to give 8-hydroxy-5-methoxymethyl-1,2,3,4-tetrahydroisoquinoline (2). By using of the rearrangement synthesis of litebamine (4) was carried out.