Alcohols, Ethers, and Epoxides

All three compounds contain an O atom that is sp hybridized and tetrahedral (9.2). 

All three compounds have polar C-O bonds, but only alcohols have an 0-H bond for intermolecular hydrogen bonding (9.4). 

Alcohols and ethers do not contain a good leaving group. Nucleophilic substitution can occur only after the OH (or OR) group is converted to a better leaving group (9.7A). 

Epoxides have a leaving group located in a strained three-membered ring, making them reactive to strong nucleophiles and acids HZ that contain a nucleophilic atom Z (9.15). 

Less stable carbocations rearrange to more stable carbocations by shift of a hydrogen atom or an alkyl group. Besides rearrangement, carbocations also react with nucleophiles (7.13) and bases (8.6). 

General features—Reactions of alcohols, ethers, and epoxides 

12 Conversion of alcohols to alkyl halides with SOCI2 and PBt3 

Although alcohols, ethers, and epoxides share many characteristics, each functional group has its own distinct reactivity, making each unique and different from the alkyl halides studied in Chapters 7 and 8. Appreciate the similarities but pay attention to the differences. 

Alcohols, ethers, and epoxides are three functional groups that contain carbon-oxygen a bonds. 

Alcohols contain a hydroxy group (OH group) bonded to an sp hybridized carbon atom. Alcohols are classified as primary (1°), secondary (2°), or tertiary (3°) based on the number of carbon atoms bonded to the carbon with the OH group. 

In Chapter 9, we take the principles learned in Chapters 7 and 8 about leaving groups, nucleophiles, and bases, and apply them to alcohols, ethers, and epoxides, three new functional groups that contain polar C-O bonds. In the process, you will discover that all of the reactions in Chapter 9 follow one of the four mechanisms introduced in Chapters 7 and 8—SnI, Sn2, El, or E2— so there are no new general mechanisms to learn. 

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Electrostatic potential maps for a simple alcohol, ether, and epoxide... 

Alcohols, ethers, and epoxides each contain an oxygen atom surrounded by two atoms and two nonbonded electron pairs, making the O atom tetrahedral and sp hybridized. Because only two of the four groups around O are atoms, alcohols and ethers have a bent shape like H2O. 

Alcohols, ethers, and epoxides exhibit dipole-dipole interactions because they have a bent structure with two polar bonds. Alcohols are also capable of intermolecular hydrogen bonding,... 

How these factors affect the physical properties of alcohols, ethers, and epoxides is summarized in Table 9.1. 

Alcohols, ethers, and epoxides having < 5 C s are H2O soluble because they each have an oxygen atom capable of hydrogen bonding to H2O (Section 3.4C). 

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