Ingold-Prelog procedure

The prefix (RS) is used to denote a racemic modification. For example, (RS)-Sec butyl chloride. The symbols R and S are applied to eompounds whose absolute stereochemistry has been determined. However, while applying the nomenelature to projection formulae of compounds containing several asymmetric centres Cahn, Ingold. Prelog procedures are supplemented by the following conversion rule. 

Sequence rule (Section 7 6) Foundation of the Cahn-Ingold-Prelog system It is a procedure for ranking substituents on the basis of atomic number... 

There are many procedures to determine the chirality sense of a stereomodcl, the best known being the R and S descriptors of the Cahn-Ingold Prelog (CIP) system. 

The substituents are listed according to the priority rules of Cahn-Ingold-Prelog in descending order. Preparative procedures are marked by a page number in bold-face type. Educts (starting material) as opposed to products are marked by a page number in italic-face type. 

In the stereochemical nomenclature of coordination compounds, the procedure for assigning priority numbers to the ligating atoms of a mononuclear coordination system is based upon the standard sequence rules developed for chiral carbon compounds (the Cahn, Ingold, Prelog or CIP rules6, see Section IR-9.3.3.2). 

The procedure for assigning priorities in mononuclear coordination systems is based on the standard sequence rules developed for chiral carbon compounds by Cahn, Ingold and Prelog.13 (See also Section P-91 of Ref. 1.) These CIP rules can be used quite generally for assigning priorities to groups attached to a central atom. 

The doubly bridged allene 38 of D2 symmetry was first cited by Cahn, Ingold, and Prelog in their classic paper Specification of Molecular Chirality (7) to illustrate the procedure for specifying the axial chirality of a molecule with this unusually high symmetry. Our group reported the synthesis of the optically... 

In order to completely define the structure of an enantiomer using the information so far described, it is necessary to draw the structure of the molecule. This procedure can be clumsy and tedious and thus a system of symbols is necessary to provide the structural information in a concise and understandable manner. The use of the symbols (R) and (S) rectus and sinister) has been proposed by three chemists, R. S. Cahn (the Royal Society of Chemistry), Sir Christopher Ingold (University College, London) and V. Prelog (Eidgenossiche Technische Hochschule, Zurich) to describe the structure of an enantiomer, and the format that they suggested has now been generally accepted. To define the structure two rational procedures must be carried out in two steps. 

The configurations of some molecules, such as amino acids and carbohydrates, can easily be compared to reference compounds such as D-glyceraldehyde. But this procedure is not easily applied to molecules whose structures differ considerably from the reference compound. To circumvent this difficulty, R. S. Kahn, K. C. Ingold, and V. Prelog established a set of rules in 1964 that describe the absolute configuration of any chiral molecule. 

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