Nomenclature ring oxygen replacement

Nitrogen, ring oxygen replacement by, 140-141 Nomenclature, 44-177, see also... 

The (non-detachable) prefix carba- signifies replacement of a heteroatom by carbon in general natural product nomenclature [26], and may be applied to replacement of the hemiacetal ring oxygen in carbohydrates if there is a desire to stress homomorphic relationships. If the original heteroatom is unnumbered, the new carbon atom is assigned the locant of the non-anomeric adjacent skeletal atom, with suffix a . 

We did not mention polar hydrocarbons in the crash course on organic nomenclature (Box 10.1). This term refers to compounds containing one or more nitrogen, oxygen, or sulfur atoms replacing carbon atoms in ring structures or sometimes attached to them. These... 

The nomenclature of the family of compounds to be discussed below has for long been the cause of much confusion. The systematic name for a six-membered ring containing one sulfur atom is thiin, but Chemical Abstracts uses the name thiopyran, while many earlier publications have used the replacement nomenclature thiapyran (which is strictly inaccurate as thia implies replacement of carbon, rather than oxygen, by sulfur). Throughout this chapter the terms thiopyran and thiin will be used interchangeably, while thiadecalin nomenclature will be found convenient for the perhydrobenzothiopyran systems. 

Cyclic ethers can be named in several ways. One simple way is to use teplacement nomenclature, in which we relate the cyclic ether to the corresponding hydrocarbon ring system and use the prefix oxa- to indicate that an oxygen atom replaces a CH2 group. In another system, a cyclic three-membered ether is named oxirane and a four-membered ether is called oxetane. Several simple cyclic ethers also have common names in the examples below, these common names are given in parentheses. Tetrahydrofuran (THF) and 1,4-dioxane are useful solvents ... 

Chapter 21 introduces aromatic hydrocarbons and their unique chemistry. In another class of aromatic compounds, heteroatoms replace one or more of the ring carbons. These compounds are collectively known as heterocycles or heterocyclic aromatic compounds, and they comprise a class of compounds so large that an entire course is easily built around their chemistry. Heterocycles are seen in several places in this book, including a brief introduction to their nomenclature in Chapter 5 (Section 5.6) and in Chapter 8 (Section 8.9). The most common heterocycles include five- and six-membered monocyclic derivatives that contain nitrogen, oxygen, or sulfur. Several important bicyclic derivatives contain nitrogen. The use of heterocycles in medicine and industry is extensive. This chapter will expand the aromatic chemistry from Chapter 21 and introduce the world of heterocyclic chemistry. 

In addition, names may be formed from any hydrocarbon by indicating replacement of a ring member by, for instance, oxygen, sulphur, or nitrogen by oxa-, thia-, aza-prefixes, respectively. The numbering of the hydrocarbon is retained by this procedure, and if more than one kind of heteroatom is present they are cited in a prescribed order (e.g.j that just given). An example would be 8ff-7-thia-l,9-diaza-phenanthrene (XXI). This nomenclature must be applied to the hydrocarbon parent , not to a... 

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