Additions, IUPAC rules

As we cover new functional groups in later chapters, the applicable IUPAC rules of nomenclature will be given. In addition, Appendix A at the back of this book gives an overall view of organic nomenclature and shows how compounds that contain more than one functional group are named. For the present, let s see how to name branched-chain alkanes and learn some general naming rules that are applicable to all compounds. 

IUPAC/Chemical Abstracts System (IUPAC Rule B-3). The fusion operations described in Section II, A, 3, a are applied to trivial and/or Hantzsch-Widman names of heterocyclic (and, if present, car-bocyclic) components see examples 25-27. In addition a unit consisting of a benzene ring fused to a one-ring heterocycle can be considered as a single component. If this one-ring heterocycle contains 3-10 members it... 

The scope of this problem can be indicated by a brief consideration of the stereochemical nomenclature of hydroxy derivatives of the bicyclic terpenes. For the parent bicyclic hydrocarbon compound known in the literature at present as cam-phane, the name "bomane is recommended in this report. (Reasons for choosing "bornane are discussed later under "The Bornane Hydrocarbons .) A mono-hydroxy derivative of bornane, on the basis of IUPAC rules (41), would be named as a bornanol. Two such derivatives have the common terpene names, bomeol and isobomeol these names, on the basis of recommendations in this report would both become 2-bornanol. Obviously, this is inadequate and additional designations are necessary to distinguish between die two stereoisomers. 

Benzo and other fused derivatives are also known. In addition, the 1,2-dithiole ring is an integral part of the structure of the l,6,6aA4-trithiapentalenes (5) covered in Chapter 4.38. Naming in this chapter will conform mostly to that used in Chemical Abstracts except for the dithiolylium cation (4) (IUPAC Rule C-83) and also for the trithiapentalenes. 

The enormous growth in organometallic chemistry over the last fifty years and the discovery of new classes of compounds with unprecedented bonding modes has resulted in the need for additional nomenclature rules for organometallic compounds. This Chapter is therefore considerably expanded over Section 1-10.9 of Ref. 1 and is largely based on the IUPAC recommendations published in 1999 for organometallic compounds of the transition elements.2... 

In this book we use the Nomenclature of Organic Chemistry of the International Union of Pure and Applied Chemistry, 1979 Edition ( Blue book , IUPAC, 1979), the Revised Nomenclature for Radicals, Ions, Radical Ions, and Related Species (IUPAC, 1993), and additional rules applied by the Chemical Abstracts Service for the 1987-1991 Index Guide Chemical Abstracts, 1992). 

For purely alicyclic compounds, the selection process proceeds successively until a decision is reached (a) the maximum number of substituents corresponding to the characteristic group cited earliest in Table 1.7, (b) the maximum number of double and triple bonds considered together, (c) the maximum length of the chain, and (d) the maximum number of double bonds. Additional criteria, if needed for complicated compounds, are given in the IUPAC nomenclature rules. 

In the third edition I included the new IUPAC names for organic transformations. Since then the rules have been broadened to cover additional cases hence more such names are given in this edition. Furthermore, IUPAC has now published a new system for designating reaction mechanisms (see p. 290), and I now include some of the simpler of these new designations. 

An additional feature of IUPAC nomenclature that concerns the direction of numbering is the first point of difference rule. Consider the two directions in which the following alkane may be numbered ... 

After the acceptance of the rules just mentioned, international work on nomenclature practically came to a standstill until the International Union of Pure and Applied Chemistry (IUPAC) was formed in 1919. This organization appointed a Commission for the Reform of the Nomenclature of Organic Chemistry the work of this Commission, carried out under Holleman s leadership from 1924 to 1930, led to the adoption of the already mentioned Definitive Report (11) containing the Li6ge Rules, a considerably improved version of the Geneva Rules. Since then this international commission, later named the Commission on the Nomenclature of Organic Chemistry, has put forward a number of improvements and additions to the Li6ge Rules these will be referred to later in another connection. 

---