Heterocyclic compounds Cyclic organic heteroatoms, atoms other than

Heterocycles are cyclic organic compounds in which one or more carbon atoms is replaced by heteroatoms, atoms other than CorH. 

Atoms other than carbon and hydrogen that appear in organic compounds are called heteroatoms. Cyclic organic compounds that contain one or more heteroatoms are called heterocycles. Heterocyclic compounds are the largest class of organic compounds and can be either aromatic (such as pyridine, pyrrole, and furan) or nonaromatic (such as piperidine, pyrrolidine, and tetrahydrofuran). 

A coirpound does not have to be a hydrocarbon to be aromatic. Many heterocyclic compounds are aromatic. A heterocyclic compound is a cyclic compound in which one or more of the ring atoms is an atom other than carbon. The atom that is not carbon is called a heteroatom. The name comes from the Greek word heteros, which means different. The most common heteroatoms encountered in organic compounds are N, O, and S. 

HETCOR (Section 13 19) A 2D NMR technique that correlates the H chemical shift of a proton to the chemical shift of the carbon to which it is attached HETCOR stands for heteronuclear chemical shift correlation Heteroatom (Section 1 7) An atom in an organic molecule that IS neither carbon nor hydrogen Heterocyclic compound (Section 3 15) Cyclic compound in which one or more of the atoms in the nng are elements other than carbon Heterocyclic compounds may or may not be aromatic... 

Organic chemistry is the study of carbon (C) compounds, all of which have covalent bonds. Carbon atoms can bond to each other to form open-chain compounds, Fig. 1.1(a), or cyclic (ring) compounds, Fig. 1.1(c). Both types can also have branches of C atoms, Fig. 1.1(b) and (d). Saturated compounds have C atoms bonded to each other by single bonds, C—C unsaturated compounds have C s joined by multiple bonds. Examples with double bonds and triple bonds are shown in Fig. 1.1(c). Cyclic compounds having at least one atom in the ring other than C (a heteroatom) are called heterocyclics, Fig. 1.1 (/). The heteroatoms are usually oxygen (O), nitrogen (N), or sulfur (S). 

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