Enantiomerically pure compound synthesis by asymmetric glyoxylate–ene reaction with vinylic sulfides and selenides catalysed by a chiral titanium complex

1993 ◽  
Vol 0 (3) ◽  
pp. 327-328 ◽  
Author(s):  
Masahiro Terada ◽  
Satoru Matsukawa ◽  
Koichi Mikami
Keyword(s):  
Pure Compound ◽  
Ene Reaction ◽  
Enantiomerically Pure ◽  
Titanium Complex ◽  
Compound Synthesis

Single-pass zone refining preparation of an enantiomerically pure compound

1967 ◽  
Vol 32 (9) ◽  
pp. 2901-2903 ◽  
Author(s):  
Lowell G. Tensmeyer ◽  
P. W. Landis ◽  
Frederick J. Marshall
Keyword(s):  
Zone Refining ◽  
Pure Compound ◽  
Enantiomerically Pure ◽  
Single Pass

Synthetic Access to a Novel Binaphthyl Ligand Bearing a Phosphine and a Triazole Donor Site

2009 ◽  
Vol 64 (11-12) ◽  
pp. 1438-1448 ◽  
Author(s):  
Claudia May ◽  
Yu Sun ◽  
Gotthelf Wolmershäuser ◽  
Werner R. Thiel
Keyword(s):  
Crystal Structure ◽  
Coordination Chemistry ◽  
Structure Analysis ◽  
Donor Site ◽  
Crystal Structure Analysis ◽  
Pure Compound ◽  
Enantiomerically Pure ◽  
X Ray ◽  
First Time

The combination of a diphenylphospinyl and a triazol-3-yl unit was realized for the first time at a 1,1'-binaphthyl backbone. This novel type of P,N-ligand is accessible as an enantiomerically pure compound in just a few steps. First experiments on the coordination chemistry with palladium(II) chloride have been carried out. A series of intermediates and a binuclear palladium(II) complex could be characterized by X-ray crystal structure analysis

Synthetic Studies Concerning the Crinine Alkaloid Haemultine

2013 ◽  
Vol 66 (1) ◽  
pp. 30 ◽  
Author(s):  
Nadia (Yuqian) Gao ◽  
Xinghua Ma ◽  
Laurent Petit ◽  
Brett D. Schwartz ◽  
Martin G. Banwell ◽  
...  
Keyword(s):  
Double Bond ◽  
Natural Product ◽  
Trifluoroacetic Acid ◽  
Spectroscopic Data ◽  
Ene Reaction ◽  
Enantiomerically Pure ◽  
Racemic Form ◽  
Pure Compounds ◽  
First Time ◽  
Bond Isomer

The racemic form, (±)-1, of the structure originally assigned to the crinine alkaloid haemultine has been prepared for the first time. A key step involved the conversion of compound (±)-4 into the isomeric cis-C3a-arylhexahydroindole (±)-3 using a Pd0-catalysed intramolecular Alder-ene reaction. The amino-alcohol (±)-2 derived from the latter compound reacted with paraformaldehyde in the presence of trifluoroacetic acid to give, via a Pictet–Spengler reaction, the target (±)-1. The diastereoisomeric Mosher esters 15 and 16 obtained by coupling the racemate (±)-1 with the R-form, 14, of the Mosher acid could be separated chromatographically and then reductively cleaved to give the enantiomerically pure compounds (+)-1 and (–)-1, respectively. The physical and spectroscopic data derived from the former enantiomer are consistent with the proposition that the title natural product is, in fact, a mixture of (+)-1 and its Δ2,3-double bond isomer.

C-O Ring Natural Products: (-)-Serotobenine (Fukuyama-Kan), (-)-Aureonitol (Cox), Salmochelin SX (Gagné), Botcinin F (Shiina), (-)-Saliniketal B (Paterson), Haterumalide NA (Borhan)

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Indole Alkaloid ◽  
Chiral Auxiliary ◽  
Michigan State University ◽  
State University ◽  
Ene Reaction ◽  
Enantiomerically Pure ◽  
Cambridge University ◽  
Stereogenic Centers ◽  
Ready Access ◽  
The University

Tohru Fukuyama of the University of Tokyo and Toshiyuki Kan of the University of Shizuoka devised ( J. Am. Chem. Soc. 2008, 130, 16854) the chiral auxiliary-directed Rh-mediated cyclization of 1, setting the two stereogenic centers of 2 with high stereocontrol. The ester 2 was carried on to the indole alkaloid (-)-Serotobenine 3. In the course of a synthesis of (-)-Aureonitol 6, Liam R. Cox of the University of Birmingham developed (J. Org. Chem. 2008, 73, 7616) the diastereoselective intramolecular addition of an allyl silane 4 to give the tetrahydrofuran 5. In analogy to what is known about the intramolecular ene reaction, the diastereocontrol observed for this cyclization may depend on the allyl silane being Z. Michel R. Gagné of the University of North Carolina found (J. Am. Chem. Soc. 2008, 130, 12177) that the Ni-catalyzed coupling of organozinc halides could be extended to glycosyl halides such as 7. This opened ready access to C -alkyl and C -aryl glycosides, including Salmochelin SX 10. Isamu Shiina of the Tokyo University of Science established (Organic Lett. 2008, 10, 3153) that the acid-mediated cyclization of the Sharpless-derived epoxide 10 proceeded with clean inversion, to give 11. The highly-substituted tetrahydropyran core 11 was then elaborated to the antifungal Botcinin F 12. Ian Paterson of Cambridge University optimized (Organic Lett. 2008, 10, 3295) the Pd-catalyzed spirocyclization of the ene diol 13, leading to 14, the enantiomerically-pure bicyclic core of (-)-Saliniketal B 15. Haterumalide NA 18 presented the particular challenge of assembling the geometrically-defined chloroalkene, in addition to closing the macrolide ring. Babak Borhan of Michigan State University addressed (J. Am. Chem. Soc. 2008, 130, 12228) both of these challenges together, electing to employ a chlorovinylidene chromium carbenoid, as developed by Falck and Mioskowski, to effect the macrocyclization of 16 to 17.

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