4-MED101_Alcohols_Phenols_Ethers.pptx

MED100 MOLECULAR AND CELLULAR MEDICAL SCIENCES I Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected]  Lecture Presentation...

MED100 MOLECULAR AND CELLULAR MEDICAL SCIENCES I Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected]  Lecture Presentation Alcohols, Phenols, Ethers Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I In this Chapter; You will learn Structure and Nomenclature Nomenclature of Alcohols Ethers Nomenclature of Ethers Exercises  Have you ever walked into a bakery and caught a whiff of vanilla or peppermint emanating from a cake or pastry? Maybe you like to snack on licorice. These smells and flavors, as well as many others that you encounter in daily life, arise from naturally occurring molecules that contain either an alcohol or an ether functional group. Hundreds of such molecules are known, and in addition to their use as flavorings, some have other commercial roles, for example, as antifreezes or pharmaceuticals. An understanding of the physical properties and reactivity of these compounds will enable you to see how they can be used to create new materials with different and even more valuable characteristics. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Structure and Nomenclature Alcohols have a hydroxyl (−OH) group bonded to a saturated carbon atom. The alcohol carbon atom may be part of a simple alkyl group, as in some of the following examples, or it may be part of a more complex molecule, such as cholesterol. Alcohols are classified as 1°, 2°, or 3°, depending on the number of carbons bonded to the alcohol carbon. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Structure and Nomenclature Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Structure and Nomenclature The alcohol carbon atom may also be a saturated carbon atom adjacent to an alkenyl group, in which case it is called allylic, or the carbon atom may be a saturated carbon atom that is attached to a benzene ring in which case it is called benzylic. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Structure and Nomenclature Compounds that have a hydroxyl group attached directly to a benzene ring are called phenols. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Structure and Nomenclature Ethers differ from alcohols in that the oxygen atom of an ether is bonded to two carbon atoms. The hydrocarbon groups may be alkyl, alkenyl, vinyl, alkynyl, or aryl. Several examples are shown here: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Alcohols Methyl alcohol (also called methanol) has the structural formula CH3OH and is the simplest member of a family of organic compounds known as alcohols. The characteristic functional group of this family is the hydroxyl (−OH) group attached to an sp3- hybridized carbon atom. Another example of an alcohol is ethyl alcohol, CH3CH2OH (also called ethanol). Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Alcohols Alcohols may be viewed structurally in two ways: (1) as hydroxyl derivatives of alkanes and (2) as alkyl derivatives of water. Ethyl alcohol, for example, can be seen as an ethane molecule in which one hydrogen has been replaced by a hydroxyl group or as a water molecule in which one hydrogen has been replaced by an ethyl group: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Alcohols As with alkyl halides, alcohols are classified into three groups: ✔ Primary (1°), ✔ Secondary (2°), and ✔ Tertiary (3°) alcohols. This classification is based on the degree of substitution of the carbon to which the hydroxyl group is directly attached. If the carbon has only one other carbon attached to it, the carbon is said to be a primary carbon and the alcohol is a primary alcohol: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Alcohols If the carbon atom that bears the hydroxyl group also has two other carbon atoms attached to it, this carbon is called a secondary carbon, and the alcohol is a secondary alcohol: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Alcohols If the carbon atom that bears the hydroxyl group has three other carbons attached to it, this carbon is called a tertiary carbon, and the alcohol is a tertiary alcohol: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Alcohols Exercises: Give IUPAC names for the following alcohols: Answers: The longest chain to which the hydroxyl group is attached gives us the base name. The ending is -ol. We then number the longest chain from the end that gives the carbon bearing the hydroxyl group the lower number. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Ethers Ethers have the general formula R−O−R or R−O−R′, where R′ may be an alkyl (or phenyl) group different from R. Ethers can be thought of as derivatives of water in which both hydrogen atoms have been replaced by alkyl groups. The bond angle at the oxygen atom of an ether is only slightly larger than that of water: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Ethers One way of naming ethers is to name the two alkyl groups attached to the oxygen atom in alphabetical order and add the word ether. If the two alkyl groups are the same, we use the prefix di-, for example, as in dimethyl ether. Write bond-line structural formulas for (a) diethyl ether, (b) ethyl propyl ether, and (c) ethyl isopropyl ether. (b) (c) (a) Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Ethers What name would you give to Me- methyl Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Ethers Simple ethers are frequently given common functional class names. One simply lists (in alphabetical order) both groups that are attached to the oxygen atom and adds the word ether: IUPAC substitutive names should be used for complicated ethers, however, and for compounds with more than one ether linkage. In this IUPAC style, ethers are named as alkoxyalkanes, alkoxyalkenes, and alkoxyarenes. The −OR group is an alkoxy group. Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Nomenclature of Ethers Cyclic ethers can be named in several ways. One simple way is to use replacement 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: Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Exercises Give an IUPAC substitutive name for each of the following alcohols Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I  Exercises Write structural formulas for each of the following A. 1-Ethylcyclobutanol B. 2-Ethoxypentane C. 2-Ethoxyethanol D. 2-Chlorohex-3-yn-1-ol E. Ethyl phenyl ether F. Tetrahydrofuran Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED100 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I Altınbas University Lecturer: Asst. Prof. Behiye ÖZTÜRK ŞEN [email protected] MED101 MOLECULLAR AND CELLULAR MEDICAL SCIENCES I