120883-62-7Relevant academic research and scientific papers
A stereoselective approach to the azaspiro[5.5]undecane ring system using a conjugate addition/dipolar cycloaddition cascade: Application to the total synthesis of (±)-2,7,8-epi-perhydrohistrionicotoxin
Wilson, Michael S.,Padwa, Albert
, p. 9601 - 9609 (2008)
(Chemical Equation Presented) An efficient stereocontrolled route to the spirocyclic perhydrohistrionicotoxin derivative (±)-2,7,8-epi- PHTx (4) is described. The reaction of 2-butyl-3-(methoxymethoxy)cyclohexanone oxime with 2,3-bis(phenylsulfonyl)-1,3-b
A Stereoselective Organopalladium Route toward Perhydrohistrionicotoxin
Tanner, David,Sellen, Mikael,Baeckvall, Jan-E.
, p. 3374 - 3378 (2007/10/02)
An efficient stereocontrolled route to the spirocyclic alkaloid perhydrohistrionicotoxin (2) is described.The readily available 2-substituted 1,3-cyclohexadiene 4 was converted regio- and stereoselectively to the chloro acetate 5 by using organopalladium methodology.Chemoselective SN2' displacement of the chloride via a copper-catalyzed Grignard reaction furnished 6, thus establishing the correct relative configuration at two adjacent centers.Further elaboration to the δ-amino alkene 10 was followed by a completely stereoselective iodocyclization reaction which yielded azaspirocycle 11.This compound was transformed to depentylperhydrohistrionicotoxin (3) in essentially one operation, thus completing a formal total synthesis of the title alkaloid.The overall yield of 3 from 4 was 23percent for nine operations.An alternative route to advanced intermediate 8 was also developed, the key step being the coupling of enol triflate 15 with the appropriate lithium organocuprate reagent.
