Boc-Phenylglycine:  The Reagent of Choice for the Assignment of the Absolute Configuration of α-Chiral Primary Amines by1H NMR Spectroscopy

1999 ◽  
Vol 64 (13) ◽  
pp. 4669-4675 ◽  
Author(s):  
José Manuel Seco ◽  
Emilio Quiñoá ◽  
Ricardo Riguera
Keyword(s):  
Nmr Spectroscopy ◽  
Absolute Configuration ◽  
Primary Amines ◽  
The Absolute

Role of Barium(II) in the Determination of the Absolute Configuration of Chiral Amines by1H NMR Spectroscopy

2006 ◽  
Vol 71 (3) ◽  
pp. 1119-1130 ◽  
Author(s):  
Rosa García ◽  
José M. Seco ◽  
Saulo A. Vázquez ◽  
Emilio Quiñoá ◽  
Ricardo Riguera
Keyword(s):  
Nmr Spectroscopy ◽  
Absolute Configuration ◽  
Chiral Amines ◽  
The Absolute

An Approach for Determining the Absolute Configuration of C-2 in 2-Oxygenated Phenylethanoid Glycosides by 1H NMR Spectroscopy

2016 ◽  
Vol 18 (16) ◽  
pp. 4084-4087 ◽  
Author(s):  
Si-Yuan Shao ◽  
Fan Zhang ◽  
Ya-Nan Yang ◽  
Zi-Ming Feng ◽  
Jian-Shuang Jiang ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Absolute Configuration ◽  
1H Nmr Spectroscopy ◽  
Phenylethanoid Glycosides ◽  
The Absolute

Synthese und Absolute Konfiguration von (+)-1-Amino-2-propanthiol·HCl / Synthesis and Absolute Configuration of ( + )-1-Amino-2-propanethiol · HCl

1987 ◽  
Vol 42 (5) ◽  
pp. 617-622 ◽  
Author(s):  
Sigurd Elz ◽  
Martin Dräger ◽  
Hans-Joachim Sattler ◽  
Walter Schunack
Keyword(s):  
Nmr Spectroscopy ◽  
Absolute Configuration ◽  
X Ray ◽  
Single Diastereomer ◽  
Important Intermediate ◽  
The Absolute ◽  
C Nmr

)-4a-The structure of (-)-5-methyl-2-phenylthiazolidine (( -)-4a), an intermediate in the synthesis of (+)-1-amino-2-propanethiol · HCl ((+)-2 · HCl), was elucidated by 1H and 13C NMR spectroscopy. In contrast to earlier findings it was shown that the important intermediate ( -)-4a is not a single diastereomer but represents a 1:1 mixture of (2R,5Sand ((2S,5S)-4a-diastereomers. The absolute configuration of the (2S,3S)-di-O-(4-toluoyl)tartrate of the disulfide (5) derived from (+)-2 · HCl was determined to be (S,S) using X-ray technique.

Determination of the absolute configuration of a secondary alcohol by NMR spectroscopy using difluorodinitrobenzene

1999 ◽  
Vol 40 (51) ◽  
pp. 9081-9084 ◽  
Author(s):  
Ken-ichi Harada ◽  
Youhei Shimizu ◽  
Atsuko Kawakami ◽  
Kiyonaga Fujii
Keyword(s):  
Nmr Spectroscopy ◽  
Absolute Configuration ◽  
Secondary Alcohol ◽  
The Absolute

A facile synthesis of methyl 3,6-dideoxy-α-L-xylo-hexopyranoside (colitose)

1978 ◽  
Vol 56 (20) ◽  
pp. 2686-2690 ◽  
Author(s):  
David R. Bundle ◽  
Staffan Josephson
Keyword(s):  
Nmr Spectroscopy ◽  
Absolute Configuration ◽  
Catalytic Hydrogenation ◽  
Major Product ◽  
Facile Synthesis ◽  
The Absolute

Methyl 3,6-dideoxy-α-L-xylo-hexopyranoside (7) bas been synthesised in four steps from methyl α-L-fucopyranoside. The intermediate methyl 3,4-O-benzylidene-α-L-fucopyranoside was separated into the S (1a) and R (1b) diastereoisomers and the absolute configuration established by proton and carbon-13 nmr spectroscopy. Under the conditions of the Hanessian–Hullar reaction methyl 4-O-benzoyl-3-bromo-3,6-dideoxy-α-L-gulopyranoside was the major product. Each diastereoisomer 1a or 1b gave identical products and product ratios; the stereochemistry and relative proportions of these products were determined by proton and carbon-13 nmr. The synthesis of ascarylose from methyl α-L-rhamnopyranoside by an analogous route is also reported. The bromo deoxy intermediates were reduced to the dideoxy sugars by catalytic hydrogenation with palladium.

Immobilisierung von Cytidin und Uridin über 2'.3'-O-cyclische Acetalderivate an Agarose / Im mobilisation of Cytidine and Uridine via 2',3'-O-Cyclic Acetal Derivatives to Agarose

1978 ◽  
Vol 33 (1-2) ◽  
pp. 56-60 ◽  
Author(s):  
Frank Seela ◽  
Helmut Roseineyer
Keyword(s):  
Nmr Spectroscopy ◽  
Absolute Configuration ◽  
Alkaline Hydrolysis ◽  
Carboxyl Groups ◽  
Cyclic Acetal ◽  
Ethyl Group ◽  
Ethyl Levulinate ◽  
The Absolute ◽  
Hydrolysis Of ◽  
C Nmr

Abstract Condensation of cytidine or uridine with ethyl levulinate leads to the acetals 1a/2a. The reac­tion would be expected to give mixtures of diastereoisom ers. As shown by 1H and 13C NMR spectroscopy only one diastereoisomer is formed. By spectroscopic comparison of 1a/2a with the corresponding adenosine acetal the absolute configuration of the new chiral centre was found to be R. The acetal m ethyl group of 1a/2a in exo-location can serve to distinguish the two m ethyl signals of O-2′,3′-isopropylidenecytidine and -uridine in the NM R spectra. On alkaline hydrolysis of the esters the acids 1b and 2b are formed, which can be condensed through their carboxyl groups with 6-aminohexylagarose. The affinity resins 3 and 4 contain 7.1 μmol and 7.6 μmol ligand/g moist gel respectively. A biospecificity of the new polymers to cytidine-and uridine converting enzymes is expected.

scholarly journals Stereochemistry of Two Hydroxybiflavanonols from Garcinia cola Nuts

1987 ◽  
Vol 42 (7-8) ◽  
pp. 855-857 ◽  
Author(s):  
Johann Sonnenbichler ◽  
Ifeanyi Madubunyi ◽  
Hugo Scheer
Keyword(s):  
Nmr Spectroscopy ◽  
Absolute Configuration ◽  
Room Temperature ◽  
H Nmr ◽  
The Absolute

The absolute configuration of two hydroxybiflavanonols from Garcinia cola nuts have been determined by CD and 500 MHz 1H NMR spectroscopy. Additionally the occurrence of atrop-isomers at room temperature as the consequence of rotational hindrance in the molecules could be demonstrated.

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