- Stereoselective Additions of Chiral α-Sulfinyl Ketimine Anions to Ene Esters. Asymmetric Syntheses of Indoloquinolizidine and Yohimban Alkaloids
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The in-situ 1,4-addition/ring-closure reactions of chiral α-sulfinyl ketimine anions with acyclic and cyclic ene esters offer a simple, convenient route for the construction of chiral cyclic alkaloids having a nitrogen-atom ring juncture.Asymmetric induction in the conjugate-addition reaction of the carbanions derived from α-sulfinyl ketimines possessing chiral sulfur with various cyclic and acyclic ene esters, subsequent ring-closure reaction, and reduction of the resulting β-sulfinyl enamides were utilized in the syntheses of (-)-1,2,3,4,6,7,12,12b-octahydroindoloquinolizine , (-)-alloyohimban , (+)-3-epi-alloyohimban , and (-)-yohimban .
- Hua, Duy H.,Bharathi, S. Narasimha,Panangadan, Jagath A. K.,Tsujimoto, Atsuko
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p. 6998 - 7007
(2007/10/02)
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- Asymmetric Total Syntheses of Elaeokanines A and B via α-Sulfinyl Ketimine
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α-Lithiated (+)-(R)-4,5-dihydro-2-methyl>-3H-pyrrole (4) underwent annulation with 1,3-diiodopropane to give (-)-(S,S)-1,2,3,5,6,7-hexahydro-8-indolizine (6), which was converted into (-)-elaeokanine B (three steps) and (+)-elaeokanine A (four steps).
- Hua, Duy H.,Bharati, S. Narashima,Robinson, Paul D.,Tsujimoto, Atsuko
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p. 2128 - 2132
(2007/10/02)
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- Stereoselective Addition Reactions of Chiral α-Sulfinyl Ketimine Anions with Ene Esters. Facile Asymmetric Syntheses of Indoloquinolizidine and Yohimbanoid Alkaloids
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A convenient route for the construction of chiral indolizidines and yohimbanoid alkaloids from the 1,4-addition/ring-closure reactions of α-sulfinyl ketimine anions with ene esters is presented.
- Hua, Duy H.,Bharathi, S. Narasimha,Takusagawa, Fusao,Tsujimoto, Atsuko,Panangadan, Jagath A. K.,et al.
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p. 5659 - 5662
(2007/10/02)
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