A concise synthesis of (±) and a total synthesis of (+)-epiquinamide
摘要:
A total synthesis of the quinolizidine alkaloid (+)-epiquinamide 1 has been achieved starting from (-)-pipecolinic acid 3. The key step is the highly diastereoselective addition of a TBDMS-protected propargyl alcohol to a chiral aldehyde derived from 3 to give erythro alkynol 19, which is then easily transformed into the desired bicyclic skeleton. (c) 2006 Elsevier Ltd. All rights reserved.
Divergent Method to <i>trans</i>-5-Hydroxy-6-alkynyl/alkenyl-2-piperidinones: Syntheses of (−)-Epiquinamide and (+)-Swainsonine
作者:Chang-Mei Si、Zhuo-Ya Mao、Han-Qing Dong、Zhen-Ting Du、Bang-Guo Wei、Guo-Qiang Lin
DOI:10.1021/acs.joc.5b00803
日期:2015.6.5
An efficient diastereoselective approach to access trans-5-hydroxy-6-alkynyl/alkenyl-2-piperidinones has been developed through nucleophilic addition of α-chiral aldimines using alkynyl/alkenyl Grignardreagents. The diastereoselectivity of alkenyl in C-6 position of 2-piperidinone was controlled by α-alkoxy substitution, while the alkynyl was controlled by the coordination of the α-alkoxy substitution
Hydroxy propiolate rearrangement to conjugated diene, Sharpless asymmetric dihydroxylation and one-pot quinolizine construction have been used as key steps in the totalsynthesis of (−)-epiquinamide.
(-)-epiquinamide (2) have been described via the key intermediate 3 obtained from the addition of 2-trialkylsilyloxyfuran 5 to N-acyliminium intermediate derived from 4. The major R,R-isomer 8 obtained from the Mannich reaction was converted into its R,S-isomer through Mitsunobu reaction. Then, a second Mitsunobu reaction of 3 led to cyano 9 and azido 11 derivatives, which were converted into 1 and 2 in 33 and
Practical Total Syntheses of Epiquinamide Enantiomers
作者:Takashi L. Suyama、William H. Gerwick
DOI:10.1021/ol061736p
日期:2006.9.1
Short and practicalsyntheses of epiquinamide and its enantiomer were accomplished with high overall yields and high stereoselectivity from readily available starting materials.
Electroreductive intramolecular coupling of aliphatic cyclic imides with ketones and O-methyloximes
作者:Naoki Kise、Kazuaki Fukazawa、Toshihiko Sakurai
DOI:10.1016/j.tetlet.2010.08.081
日期:2010.11
The electroreductive intramolecular coupling of aliphaticcyclic imides with ketones in isopropanol gave five- and six-membered cyclized products. Similarly, the electroreductive intramolecular coupling of aliphaticcyclic imides with O-methyloximes afforded five-, six-, and seven-membered cyclized products. These reactions provide a useful method to synthesize azabicyclo[n.m.0] compounds. The bicyclic