81076-52-0Relevant academic research and scientific papers
A Stereospecific Total Synthesis of (3R*,5S*,9S*)-Gephyrotoxin 223AB
Nakagawa, Yumi,Stevens, Robert V.
, p. 1871 - 1873 (1988)
The title compound was synthesized stereospecifically by the nucleophilic addition of hydride (NaCNBH3) to the conformationally rigid tetrahydropyridinium ion 6.This key intermediate was obtained in six steps from the ethylene ketal of 1-chloro-4-heptanone.Biological evaluation of 1c is also reported.
Application of Electro-Oxidative α-Cyanation of Aza-Rings to the Synthesis of Gephyrotoxin 223AB
Yang, Teng-Kuei,Yeh, Shun-Tsai,Lay, Yen-Yuan
, p. 1711 - 1716 (2007/10/02)
Six and five-membered cyclic α-cyanoamines have been prepared efficiently from N-benzylpiperidine and N-benzylpyrrolidine.These α-cyanoamines were successfully used in the synthesis of gephyrotoxin 223AB.
General Entry to the 3,5-Disubstituted Indolizidine Class of Dendrobatid Alkaloids. Total Syntheses of Both Enantiomers of Indolizidines 195B, 223AB, 239AB, and 239CD from a Common Chiral Synthon
Machinaga, Nobuo,Kibayashi, Chihiro
, p. 5178 - 5189 (2007/10/02)
A general protocol for the total syntheses of both enantiomers of dendrobatid alkaloids, indolizidines 195B, 223AB, 239AB, and 239CD, belonging to the 3,5-disubstituted indolizidine subclass is described, in which 3,4-dideoxy-D-threo-hexitol (8) has been used as single and common chiral synthon.The syntheses of the (+)- and (-)-enantiomers of these alkaloids begin with (S,S)- and (R,R)-1,2:5,6-diepoxyhexanes (7), respectively, both of which were derived from 8 in three steps and are carried out by way of pyrrolidine formation via the cyclic sulfates leading to the(2R,5R)- and (2S,5S)-trans-2,5-dialkylated pyrrolidines, which were converted to the (+)- and (-)-enantiomers, respectively, of the title indolizidine alkaloids.These syntheses involve the first chiral preparations of indolizidines 239AB, 239CD both in natural (-)- and unnatural (+)-enantiomeric forms, which confirm the absolute configurations of natural 239AB and 239CD as 3R,5S,8aR and 3R,5R,8aR, respectively.
AN INTRAMOLECULAR RING CONTRACTION APPROACH TO THE SYNTHESIS OF INDOLIZIDINE ALKALOIDS
Zeller, Emmanuel,Grierson, David S.
, p. 1575 - 1578 (2007/10/02)
Reaction of the anion of synthon 5 with PrBr followed by reductive decyanation gave the key intermediate 8.Ring opening of 8, on treatment with diethyl cyanophosphonate, produced 9.Compound 9 reacted with K plus 18-crown-6 in THF to give a 9:1 mixture of indolizidines 10 and 11.
A Short Total Synthesis of (+/-)-Gephyrotoxin-223AB
Broka, Chris A.,Eng, Kan K.
, p. 5043 - 5045 (2007/10/02)
(+/-)-Gephyrotoxin-223AB has been synthesized from 2-carbomethoxycyclopentanone in nine steps by a route utilizing the stereoselective homolytic cyclization of an alkenyl-substituted N-chloropiperidine.
Indolizine Alkaloid Synthesis. Preparation of the Pharaoh Ant Trail Pheromone and Gephyrotoxin 223 Stereoisomers
Macdonald, Timothy L.
, p. 193 - 194 (2007/10/02)
A stereoselective entry into the 3,5-dialkylindolizidine alkaloid skeleton proceeding via N1-C2 vicinal annulation of a 1,4-dibromoalkane onto a pyrroline system is described.
