Optical rotatory dispersion studies. XLI. The absolute configuration of plicatic acid

1967 ◽  
Vol 45 (3) ◽  
pp. 319-324 ◽  
Author(s):  
R. J. Swan ◽  
W. Klyne ◽  
H. MacLean
Keyword(s):  
Carboxylic Acid ◽  
Absolute Configuration ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Naturally Occurring ◽  
Dispersion Data ◽  
The Absolute

The absolute configuration of the naturally occurring lignan plicatic acid (I, 2,3,6-trihydroxy-7-methoxy-2-hydroxymethyl-4-(3′,4′-dihydroxy-5′-methoxyphenyl)-tetralin-3-carboxylic acid) is shown, by optical rotatory dispersion data, to be 2R,3S,4R.

Alkaloids of Lycopodiumlucidulum Michx. Structure and properties of alkaloid L.23

1969 ◽  
Vol 47 (3) ◽  
pp. 449-455 ◽  
Author(s):  
W. A. Ayer ◽  
B. Altenkirk ◽  
R. H. Burnell ◽  
M. Moinas
Keyword(s):  
Absolute Configuration ◽  
Cotton Effect ◽  
Ultraviolet Spectrum ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Structure And Properties ◽  
The Absolute ◽  
Related Compounds ◽  
Circular Dichroic

The minor alkaloids present among the strong bases of Lycopodiumlucidulum have been reinvestigated. Manske and Marion's alkaloid L.23 has been shown to be epimeric with lycodoline at C-12 and the nitrogen. A correlation between the two alkaloids has been achieved. The presence of a σ-coupled p interaction in the ultraviolet spectrum of lycopodine, lycodoline, and related compounds is described. A Cotton effect due to this chromophore has been detected by means of circular dichroism. The optical rotatory dispersion and circular dichroic properties of lycopodine, 12-epilycopodine, lycodoline, and alkaloid L.23 are discussed in terms of the absolute configuration assigned to these alkaloids.

Flavan derivatives. XIV. The absolute configurations of some 1,2-diarylpropane derivatives and of some isoflavans

1965 ◽  
Vol 18 (7) ◽  
pp. 1035 ◽  
Author(s):  
JW Clark-Lewis ◽  
I Dainis ◽  
GC Ramsay
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Phosphorus Pentachloride ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Aryl Group ◽  
Dispersion Data ◽  
Methylsuccinic Acid ◽  
The Absolute

The conversion of (+)-catechin tetramethyl ether into (-)-2-chloro-5,7,3',4'-tetramethoxyisoflavan is shown to proceed by 1,2-migration of the 2-aryl group with inversion of configuration at the 3-position of the flavan nucleus (the migration terminus). The chloroisoflavan was converted into (+)-cis-2-acetoxy-5,7,3',4'-tetramethoxyisoflavan and reduction of this gave (+)-2-(3,4-dimethoxyphenyl)-3-(2,4,6-trimethoxyphenyl)propan-1-ol. This was converted into the corresponding (+)-propane which gave (-)-methylsuccinic acid on ozonolysis. The (+)-propane therefore possesses the (8)-configuration corresponding to the (S)-configuration of the (+)-2,3-diarylpropan-1-ol and the (3s)-configuration of the (+)-cis-2-acetoxy-isoflavan. (+)-cis-2-Ethoxy- and (+)-cis-2-methoxy-5,7,3',4'-tetramethoxyisoflavan have been converted into the related (+)-1-alkoxy-2,3-diarylpropanes. Chlorination of the phloroglucinol nucleus in (+)-catechin tetramethyl ether may occur during reaction with phosphorus pentachloride and is shown to lead to 2,6-dichloro-5,7,3',4'-tetramethoxyisoflavan. Racemic cis- and laevorotatory and racemic trans-2-acetoxy-5,7,3',4'-tetramethoxyisoflavan have been prepared. Nuclear magnetic resonance and optical rotatory dispersion data for a number of isoflavans are reported. The absolute configurations of pterocarpin, homopterocarpin, and pisatin are inferred.

scholarly journals The absolute configuration of cryptopleurine and tylocrebrine

1978 ◽  
Vol 31 (9) ◽  
pp. 2095 ◽  
Author(s):  
E Gellert ◽  
R Rudzats ◽  
JC Craig ◽  
SK Roy ◽  
RW Woodard
Keyword(s):  
Circular Dichroism ◽  
Absolute Configuration ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Circular Dichroism Spectra ◽  
The Absolute ◽  
Circular Dichroïsm

The absolute configurations of cryptopleurine and (-)-tylocrebrine have been established as R and S respectively by comparison of their optical rotatory dispersion and circular dichroism spectra with those of tylophorine.

scholarly journals Decandrinin, an unprecedented C9-spiro-fused 7,8-seco-ent-abietane from the Godavari mangrove Ceriops decandra

2014 ◽  
Vol 10 ◽  
pp. 276-281 ◽  
Author(s):  
Hui Wang ◽  
Min-Yi Li ◽  
Félix Zongwe Katele ◽  
Tirumani Satyanandamurty ◽  
Jun Wu ◽  
...  
Keyword(s):  
Quantum Chemical Calculations ◽  
Absolute Configuration ◽  
Quantum Chemical ◽  
Andhra Pradesh ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Relative Configuration ◽  
Ceriops Decandra ◽  
The Absolute

Decandrinin (1), an unprecedented C9-spiro-fused 7,8-seco-ent-abietane, was obtained from the bark of an Indian mangrove, Ceriops decandra, collected in the estuary of Godavari, Andhra Pradesh. The constitution and the relative configuration of 1 were determined by HRMS (ESI) and extensive NMR investigations, and the absolute configuration by circular dichroism (CD) and optical-rotatory dispersion (ORD) spectroscopy in combination with quantum-chemical calculations. Decandrinin is the first 7,8-seco-ent-abietane.

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