Structures with identical packing; racemic and partially optically pure 3-(2'-chloro-2'-phenylethyl)-2-thiazolidiniminium p-toluenesulfonate and a comparison of the packing in corresponding racemic and optically active compounds

1994 ◽  
Vol 50 (6) ◽  
pp. 762-771 ◽  
Author(s):  
K. Marthi ◽  
S. Larsen ◽  
M. Ács ◽  
J. Bálint ◽  
E. Fogassy
Keyword(s):  
Optically Active ◽  
Active Compounds ◽  
Optically Pure

scholarly journals Synthesis of 2-Amino-apopinan-3-ol and Applications of Its Derivatives in Asymmetric Reduction of Ketones

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 63
Author(s):  
Anna Kmieciak ◽  
Marek P. Krzemiński
Keyword(s):  
Amino Alcohol ◽  
Asymmetric Reduction ◽  
Optically Active ◽  
Asymmetric Reactions ◽  
Transfer Hydrogenation ◽  
Asymmetric Transfer Hydrogenation ◽  
Active Compounds ◽  
Reduction Methods ◽  
Optically Pure ◽  
Reduction Of Ketones

Monoterpenes are optically active compounds which occur in nature. This fact makes them interesting precursors for the synthesis of optically active ligands, which can be applied in various asymmetric reactions. In this work, we present the synthesis of optically pure 2-amino-apopinan-3-ol from (−)-α-pinene. The obtained amino alcohol was used as a precursor of oxazaborolidine, which was used as catalyst in the asymmetric reduction of aryl-alkyl ketones with borane. In the second part, we transformed 2-amino-apopinan-3-ol into PHOX ligand in a three-step reaction. The complex of ruthenium precursor with PHOX ligand was used as a catalyst in the asymmetric transfer hydrogenation of aryl-alkyl ketones. Alcohols with enantiomeric excesses of up to 97% were isolated using both reduction methods.

Optically Active Compounds Related to Methadon

1949 ◽  
Vol 71 (2) ◽  
pp. 460-462 ◽  
Author(s):  
Albert. Pohland ◽  
Frederick J. Marshall ◽  
Thomas P. Carney
Keyword(s):  
Optically Active ◽  
Active Compounds

Synthesis and resolution of an asymmetric arsonium cation. Crystal and molecular structures of (R)-Benzyl(methyl)(4-methylphenyl)(naphthalen-1-yl)- arsonium bromide and hexafluorophosphate

1984 ◽  
Vol 37 (6) ◽  
pp. 1171 ◽  
Author(s):  
DG Allen ◽  
CL Raston ◽  
BW Skelton ◽  
AH White ◽  
SB Wild
Keyword(s):  
Ion Exchange ◽  
Absolute Configuration ◽  
Optically Active ◽  
Molecular Structures ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Ion Exchange Column ◽  
Optically Pure

The (�)-benzyl(methyl)(4-methylphenyl)(naphthalen-1-yl)arsonium cation has been synthesized and subsequently resolved by fractional crystallization of monohydrogen [R-(R*,R*)]-2,3-bis(benzoyloxy)- butanedioate salts. The separated diastereoisomers were converted into the corresponding optically active arsonium bromides by ion-exchange column chromatography. The absolute configuration of the arsonium cation exhibiting a positive rotation at 589 nm (sodium D line) has been established as (R) by single-crystal X-ray analysis of both the bromide and hexafluorophosphate salts. The arsonium bromide with [α]D + 54.8�(c, 0.62 in CH2Cl2) crystallizes in the orthorhombic space group P212121 (D24, No.19) with a 22.472(8), b 15.724(7), c 12.585(5) � and U 4447(3) �3. The corresponding hexafluorophosphate with [α]D + 19.3� (c, 0.5 in CH2Cl2) crystallizes in the same space group with a 23.56(2), b 16.40(1), c 13.12(1) � and U 5067(6) � 3. Benzylidene transfer to benzaldehyde from the arsonium ylide derived from either of the arsonium salts produced optically pure (–)-(S)-methyl(4-methylphenyl)(naphthalen-1-yl)arsine, [α]D - 115.9� (c, 0.593 in CHCl3), and partly resolved [R-(R*,R*)]-2,3-diphenyloxiran.

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