The absolute configuration of (+)-3,4-Bis(p-hydroxyphenyl)hexane (hexoestrol) and related compounds

1974 ◽  
Vol 27 (8) ◽  
pp. 1753 ◽  
Author(s):  
DJ Collins ◽  
JJ Hobbs
Keyword(s):  
Absolute Configuration ◽  
Valeric Acid ◽  
The Absolute ◽  
Related Compounds ◽  
Absolute Stereochemistry

(+)-(2S,3R)-2,3-Bis(p-methoxyphenyl)valeric acid, previously converted into (-)-(2R,3R)-2,3-bis(p-methoxyphenyl)pentane, has now been converted into (+)-(3R,4R)-3,4-bis(p-methoxyphenyl)hexane via (+)-(3S,4R)-3,4-bis(p-methoxyphenyl)hexan-2-one and (-)-(4s)-3,4-bis(p-methoxypheny1)hex-2-ene. This provides unequivocal correlation of the absolute stereochemistry of a series of homologous diarylalkanes, and a corresponding series of diarylalkenes.

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

1992 ◽  
Vol 57 (7) ◽  
pp. 1459-1465 ◽  
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.

THE REACTION OF UNSATURATED CARBOHYDRATES WITH CARBON MONOXIDE AND HYDROGEN: V. ABSOLUTE STEREOCHEMISTRY OF ANHYDRODEOXYHEPTITOLS FROM 3,4,6-TRI-O-ACETYL-D-GLUCAL. STEREOCHEMISTRY OF HYDROFORMYLATION. CONFORMATIONAL ANALYSIS

1965 ◽  
Vol 43 (5) ◽  
pp. 1375-1381 ◽  
Author(s):  
Alex Rosenthal ◽  
Hans J. Koch
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Carbon Monoxide ◽  
Absolute Configuration ◽  
Sodium Iodide ◽  
Crystallographic Analysis ◽  
X Ray ◽  
Dicobalt Octacarbonyl ◽  
The Absolute ◽  
Compound Ii ◽  
Absolute Stereochemistry

3,4,6-Tri-O-acetyl-D-glucal reacted with carbon monoxide and hydrogen in the presence of dicobalt octacarbonyl to yield a mixture of two epimeric anhydrodeoxyheptitols, namely, 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-D-manno-heptitol (I) and 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-D-gluco-heptitol (II). De-O-acetylation of the mixture, followed by chromatographic separation, yielded crystalline 2,6-anhydro-3-deoxy-D-manno-heptitol (III) and 2,6-anhydro-3-deoxy-D-gluco-heptitol (IV). Reaction of the mixture of heptitols (I) and (II) with p-bromobenzenesulfonyl chloride, followed by fractional crystallization of the brosylates, gave pure 4,5,7-tri-O-acetyl-2,6-anhydro-1-O-(p-bromophenylsulfonyl)-3-deoxy-D-gluco-heptitol (VII). The absolute configuration of (VII) has been previously established by X-ray crystallographic analysis. The absolute configuration of (III) was established by correlation with that of (VII). The conversion of compound (II) into various derivatives is described.Reaction of 3,4,6-tri-O-acetyl-D-glucal with carbon monoxide and deuterium afforded 2,6-anhydro-3-deoxy-D-manno-heptitol-1,1,3-2H3 (XIII) and 2,6-anhydro-3-deoxy-D-gluco-heptitol-1,1,3-2H3 (XIV). Examination of the nuclear magnetic resonance (n.m.r.) spectra of the normal and deuterated anhydrodeoxyheptitols confirmed the structural assignments and showed that cis addition to the double bond took place to give (XIV).Comparison of the exchange reaction of sodium iodide with 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-1-O-tosyl-D-gluco-heptitol (VIII) and with 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-1-O-tosyl-D-manno-heptitol (XV) revealed that the equatorial primary tosyloxy group of (VIII) was exchanged by iodine twice as readily as the axial primary tosyloxy group of (XV).

scholarly journals Absolute Stereochemistry of the β-Hydroxy Acid Unit in Hantupeptins and Trungapeptins

2016 ◽  
Vol 11 (1) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Deepak Kumar Gupta ◽  
Gary Chi Ying Ding ◽  
Yong Chua Teo ◽  
Lik Tong Tan
Keyword(s):  
Amino Acid ◽  
Structural Feature ◽  
Absolute Configuration ◽  
Hydroxy Acid ◽  
Hplc Analysis ◽  
The Absolute ◽  
Absolute Stereochemistry ◽  
Common Structural Feature ◽  
Acid Unit

The β-hydroxy/amino acid unit is a common structural feature of many bioactive marine cyanobacterial depsipeptides. In this study, the absolute stereochemistry of the β-hydroxy acid moieties in hantupeptins and trungapeptins were determined through their synthesis and HPLC analysis of the Mosher ester derivatives. Synthesis of two3-hydroxy-2-methyloctanoic acid (Hmoa) stereoisomers, (2 S,3 R)-Hmoa and (2 S,3 S)-Hmoa, were achieved using diastereoselective asymmetric method and the retention times of all four Hmoa isomers were established indirectly by RPLC-MS analysis of their Mosher ester derivative standards. Based on the retention times of the standards, the absolute configuration of the Hmoa unit in hantupeptin C (3) and trungapeptin C (6) was assigned as (2 R,3 S)- and (2 S,3 R)-Hmoa, respectively. The use of the Mosher's reagents, coupled with HPLC analysis, provided a viable alternative to the absolute stereochemical determination of β-hydroxy acid units in depsipeptides.

scholarly journals Determination of the Absolute Stereochemistry of Limonene and α-Santalol by Raman Optical Activity Spectroscopy

2012 ◽  
Vol 7 (4) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Akira Sakamoto ◽  
Nao Ohya ◽  
Toshio Hasegawa ◽  
Hiroaki Izumi ◽  
Nakako Tokita ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Optical Activity ◽  
Absolute Configuration ◽  
Natural Compounds ◽  
Vibrational Circular Dichroism ◽  
Raman Optical Activity ◽  
The Absolute ◽  
Circular Dichroïsm ◽  
Absolute Stereochemistry

Determining the absolute stereochemistry of organic compounds in solution remains a challenge. We investigated the use of Raman optical activity (ROA) spectroscopy to address this problem. The absolute configurations of (+)-( R)- and (-)-( S)-limonene were determined by ROA spectroscopy, which can be applied to smaller amounts of sample as compared with vibrational circular dichroism (VCD) spectroscopy. This ROA method was also applied to (+)-( E)-α-santalol and shown to be successful in the determination of the absolute configuration of this compound. ROA spectroscopy shows promise as a useful tool for determining the absolute stereochemistry of many natural compounds.

ChemInform Abstract: Chiral Lactols. Part 13. Determination of the Absolute Configuration of Aromatic Cyanohydrins and Structurally Related Compounds

ChemInform ◽  
2010 ◽  
Vol 26 (42) ◽  
pp. no-no
Author(s):  
C. R. NOE ◽  
M. KNOLLMUELLER ◽  
P. GAERTNER ◽  
E. KATIKARIDES ◽  
L. GAISCHIN ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
The Absolute ◽  
Related Compounds

Synthesis of anisomycin. Part I. The stereospecific synthesis of N-benzoyl-2-(p-methoxybenzyl)-3-hydroxy-4-carboxamido pyrrolidine and the absolute configuration of anisomycin

1968 ◽  
Vol 46 (7) ◽  
pp. 1101-1104 ◽  
Author(s):  
C. M. Wong
Keyword(s):  
Infrared Spectra ◽  
Absolute Configuration ◽  
Optical Rotation ◽  
Specific Rotation ◽  
Stereospecific Synthesis ◽  
Specific Optical Rotation ◽  
Synthetic Compound ◽  
The Absolute ◽  
Hydrolysis Of ◽  
Absolute Stereochemistry

L-Tyrosine was converted stereospecifically to N-benzoyl-2-(p-methoxybenzyl)-3-hydroxy-4-cyanopyrrolidine (10) which had a specific optical rotation [Formula: see text]. Anisomycin was converted also to N-benzoyl-2-(p-methoxybenzyl)-3-hydroxy-4-cyanopyrrolidine (16) which had a specific rotation [Formula: see text]. The infrared spectra of the synthetic compound and the derivative of anisomycin were superimposable with each other. This result showed that the absolute configuration of the three asymmetric centers in (10) of synthetic origin were 2S, 3S, 4S, and those in (16) were 2R, 3R, 4R. Thus, anisomycin should have the absolute stereochemistry 2R, 3S, 4S as depicted in the structure (2). Hydrolysis of the hydroxy nitriles (8) and (10) gave an identical amide (3) which should have the absolute stereochemistry 2S, 3S, 4R as shown in structure (3).

The Absolute Configuration of Cuauhtemone and Related Compounds

ChemInform ◽  
2003 ◽  
Vol 34 (24) ◽  
Author(s):  
J. Martin Torres-Valencia ◽  
Dora L. Quintero-Mogica ◽  
Guadalupe I. Leon ◽  
Oscar R. Suarez-Castillo ◽  
J. Roberto Villagomez-Ibarra ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
The Absolute ◽  
Related Compounds

Sterically Crowded Heterocycles. XIII. An Insight Into the Absolute Stereochemistry of Atropisomeric (Z)-3-(Imidazo[1,2-a]pyridin-3-yl)prop-2-en-1-ones

2000 ◽  
Vol 65 (10) ◽  
pp. 1643-1652
Author(s):  
Radek Pohl ◽  
Jan Sýkora ◽  
Petr Maloň ◽  
Stanislav Böhm ◽  
Bohumil Kratochvíl ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Heats Of Formation ◽  
Cd Spectra ◽  
X Ray ◽  
Space Analysis ◽  
The Absolute ◽  
Absolute Stereochemistry ◽  
Insight Into

The absolute configuration of the atropisomeric (Z)-3-(5-methyl-2-phenylimidazo[1,2-a]pyridin-3-yl)-1,3-diphenylprop-2-en-1-one was evaluated to be R for the dextrorotatory and S for the laevorotatory enantiomers. The assignment is based on their two-step syntheses via atropodiastereoisomeric carbamates prepared from the corresponding atropodiastereoisomeric alcohols with (R)-(+)-α-phenylethyl isocyanate and by a complete X-ray space analysis of the quaternary triiodide obtained from the (R)-(+)-enantiomer. CD spectra and PM3 calculated heats of formation for selected compounds are discussed in relation to the found molecular configurations.

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