Stereochemistry absolute configuration

W. Klyne and J. Buckingham, Atlas of Stereochemistry, Absolute Configurations of Organic Molecules, 2nd ed., Vol. 1, Oxford University, New York, 1978 Vol. 2, Chapman and Hall, London, 1978 J. Buckingham and R. A. Hill, Atlas of Stereochemistry, Absolute Configurations of Organic Molecules, Supplement to the Second Edition, Chapman and Hall, New York, 1986. 

W, Klyne. J. Buckingham, Atlas of Stereochemistry. Absolute Configurations of Organic Molecules, 2nd ed., Vols. 1 and 2, and Supplement. Chapman Hall, London 1978 and 1986. 

Klyne and J. Buckingham, "Atlas of Stereochemistry-Absolute Configuration of Organic Molecules", Chapman and Hall, London, (197 )-... 

Considerable progress has been made in the development of theories that can predict the complete ROA spectrum, provided that a good normal coordinate analysis is available, and this leads us to the hope that it might be possible eventually to deduce the total stereochemistry (absolute configuration, conformation, bond lengths and angles) of a chiral molecule in a chemically relevant environment from the measured ROA spectrum (or indeed from the infrared CD spectrum). 

In the following sections, the plant species that are sources of monoterpenes are not recorded unless of some special significance, and similarly for points of stereochemistry, absolute configuration, reagents, and reaction conditions. 

Atlas of stereochemistry, absolute configurations of organic molecules, second edition. Supplement. 

Supplement to Atlas of stereochemistry absolute configurations of organic moleculares/W. Hyne and J. Buckingham. 2nd ed. London, 1978. 

If the observed order of priority of the remaining three functions (a > 6 > c) is in a clockwise direction, the absolute configuration is designated R (rectus or right) if counterclockwise, the configuration is S (sinister or left). The concepts of stereochemistry and chiraUty have been extensively discussed and reviewed (27—29). 

Among the modem procedures utilized to estabUsh the chemical stmcture of a molecule, nuclear magnetic resonance (nmr) is the most widely used technique. Mass spectrometry is distinguished by its abiUty to determine molecular formulas on minute amounts, but provides no information on stereochemistry. The third most important technique is x-ray diffraction crystallography, used to estabUsh the relative and absolute configuration of any molecule that forms suitable crystals. Other physical techniques, although useful, provide less information on stmctural problems. 

For a review of chemical methods for ilctcimining absolute configuration, see Stereochemistry, Fundamentals and Methods, Vol. 3, H. B. Kagan, ed., G. Thieme, Stuttgart, 1977. 

The substance chaetochromin A, structure A, has been shown by X-ray dif action to have the absolute configuration indicated in the structure. The CD spectra of A and the related compounds cephalochromin (B) and ustilaginoidin (C) are shown in the figure. Deduce the absolute stereochemistry of cephalochromin and ustilaginoidin trom these data, and draw perspective structures indicating the absolute configuration. 

Compounds analogous to the cobaltammines may be similarly obtained using chelating amines such as ethythenediamine or bipyridyl, and these too have played an important role in stereochemical studies. Thus ct5-[Co(cn)2(NH3)Cl] was resolved into d(+) and /(—) optical i.so-mers by Werner in 1911 thereby demonstrating. to all but the most determined doubters, its octahedral stereochemistry. More recently, the absolute configuration of one of the optical isomers of [Co(en)3] was determined (.sec Panel on p, 1125),... 

The desilylacetylated qrcloadducts, produced from the reactions of trimethylsilyl-diazomethane with 3-crotonoyl-2-oxazolidinone or 3-crotonoyl-4,4-dimethyl-2-oxa-zolidinone, were transformed to methyl traws-l-acetyl-4-methyl-l-pyrazoline-5-car-boxylate through the reactions with dimethoxymagnesium at -20 °C. When the optical rotations and chiral HPLC data were compared between these two esters, it was found that these two products had opposite absolute stereochemistry (Scheme 7.39). The absolute configuration was identified on the basis of the X-ray-determined structure of the major diastereomer of cycloadduct derived from the reaction of trimethylsilyldiazomethane to (S)-3-crotonoyl-4-methyl-2-oxazolidi-none. 

Makriyannis A, Banijamali A, Van der Schyf C, Jarrell H. The role of cannabinoid stereochemistry and absolute configuration and the orientation of A9-THC in the membrane bilayer. Structure-activity relationships of cannabinoids. In Rapaka RS, Makriyannis A, eds. Interactions of Cannabinoids with Membranes. National Institute on Drug Abuse Research Monograph 79. Rockville, MD US Department of Health and Human Services, 1987. 

This oxidation method was applied to determination of the absolute stereochemistry of berberastine (HO) and thalidastine (111). (+)-Tetra-hydrojatrorrhizine (112) was converted to 5a- and 5/J-hydroxyl derivatives 113 and 114 in a 2 1 ratio (Scheme 24). The major product 113 was dehydrogenated to give rise to the dextrorotatory quaternary protoberberine 115. Thus, 110 and 111, being dextrorotatory, should have the same absolute configuration as that of 115 (77). 

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