Microwave assisted glycosylation for determining the absolute configuration of carbohydrates in plant glycosides

The reported enantioselective synthesis for the preparation of (+)-(2R,3R)-2-(4- hydroxy-3-methoxyphenyl)-3-hydroxymethyl-1,4-benzodioxane-6-carbaldehyde, precursor for the stereoselective synthesis of bioactive flavanolignans, could not be reproduced. Thus, the target molecule was prepared via the synthesis and separation of diastereomeric O-glucosides. TDDFT-ECD calculations and the 1,4-benzodioxane helicity rule were utilized to determine the absolute configuration. ECD calculations also confirmed that the 1Lb Cotton effect is governed by the helicity of the heteroring, while the higher-energy ECD transitions reflect mainly the orientation of the equatorial C-2 aryl group.

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Absolute configuration at C(20) of the derivatives of 21-nor-5α-cholane-20,24-diol

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19802443 ◽

1980 ◽

Vol 45 (9) ◽

pp. 2443-2451

Author(s):

Vladimír Pouzar ◽

Miroslav Havel

Keyword(s):

Absolute Configuration ◽

Side Chain ◽

Chemical Correlation ◽

The Absolute ◽

Derivatives Of

Derivatives of 21-nor-5α-cholane-20,24-diol XI and XIX were prepared by stepwise construction of the side-chain in the position 17β. Their absolute configuration at C(20) was determined on the basis of chemical correlation with the derivatives of 21-nor-5α-cholan-20-ol, XVI and XXIV. The absolute configuration of alcohols XVI and XXIV was determined from the ratio of the yields in which they are formed during the reduction of ketone X and using the benzoate rule. To compounds XI-XVIII the configuration 20R and to compounds XIX-XXVI the configuration 20S has been assigned.

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Absolute Stereochemistry of (-)-Wieland-Miescher Ketone as Established by the X-ray Crystallographic and CD Exciton Chirality Methods

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19921459 ◽

1992 ◽

Vol 57 (7) ◽

pp. 1459-1465 ◽

Cited By ~ 4

Author(s):

Nobuyuki Harada ◽

Tatsuo Sugioka ◽

Hisashi Uda ◽

Takeo Kuriki

Keyword(s):

Structure Analysis ◽

Absolute Configuration ◽

X Ray ◽

The Absolute ◽

Absolute Stereochemistry

The 8aR absolute stereochemistry of Wieland-Miescher ketone (-)-I was established by the X-ray structure analysis of its bis(4-bromobenzoate) derivatives (1R,6R,8aR)-(+)-IV and (1R,6S,8aR)-(-)-V. The absolute configuration of (-)-I was corroborated further by the application of the CD exciton chirality method to bis(4-bromobenzoates) (+)-IV and (-)-V.

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Rapid Organocatalytic Chirality Analysis of Amines, Amino Acids, Alcohols, Amino Alcohols and Diols with Achiral Iso(thio)cyanate Probes

Chemical Science ◽

10.1039/d1sc02061g ◽

2021 ◽

Author(s):

Eryn Nelson ◽

Jeffrey S. S. K. Formen ◽

Christian Wolf

Keyword(s):

Amino Acids ◽

Absolute Configuration ◽

Rapid Determination ◽

Amino Alcohols ◽

Enantioselective Synthesis ◽

Widespread Occurrence ◽

Chiral Compounds ◽

New Methods ◽

The Absolute

The widespread occurrence and significance of chiral compounds does not only require new methods for their enantioselective synthesis but also efficient tools that allow rapid determination of the absolute configuration,...

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Preparative-scale HPLC Resolution of Metallacyclic η3-Allyltricarbonyliron Complexes and Determination of the Absolute Configuration by X-Ray Crystal Structure Analysis

Journal of Chemical Research ◽

10.1177/174751989902300930 ◽

1999 ◽

Vol 23 (9) ◽

pp. 578-579

Author(s):

Rainer Schobert ◽

Hermann Pfab ◽

Jutta Böhmer ◽

Frank Hampel ◽

Andreas Werner

Keyword(s):

Crystal Structure ◽

Silica Gel ◽

Structure Analysis ◽

Absolute Configuration ◽

Crystal Structure Analysis ◽

Preparative Scale ◽

X Ray ◽

The Absolute

Racemates of (η3-allyl)tricarbonyliron lactone complex Fe(CO)3{η1:η3-C(O)XCH2CHCMeCH2} 1a (X = O) and (η3-allyl)tricarbonyliron lactam complex 2a (X = NMe) are resolved on a preparative scale by HPLC on cellulose tris(3,5-dimethylphenyl)carbamate/silica gel RP-8 and the absolute configuration of (-)-2a is determined by X-ray crystal structure analysis.

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Massiliamide, a cyclic tetrapeptide with potent tyrosinase inhibitory properties from the Gram-negative bacterium Massilia albidiflava DSM 17472T

The Journal of Antibiotics ◽

10.1038/s41429-020-00394-y ◽

2020 ◽

Author(s):

Andri Frediansyah ◽

Jan Straetener ◽

Heike Brötz-Oesterhelt ◽

Harald Gross

Keyword(s):

Absolute Configuration ◽

Inhibitory Activity ◽

Liquid Culture ◽

Spectroscopic Analysis ◽

2D Nmr ◽

Negative Bacterium ◽

Gram Negative ◽

The Absolute ◽

Potent Inhibitory Activity ◽

Cyclic Tetrapeptide

AbstractA cyclic tetrapeptide, designated massiliamide, was isolated from the liquid culture of the Gram-negative bacterium Massilia albidiflava DSM 17472T. The structure was elucidated through extensive spectroscopic analysis, including HR-MS and 1D and 2D NMR experiments. The absolute configuration was determined using the Marfey´s method. Massiliamide showed potent inhibitory activity towards tyrosinase with an IC50 value of 1.15 µM and no cytotoxicity.

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