Chapter 9 Learning Goals

1. You understand the substitution chemistry of alcohols: the requirement to "activate" the C-O bond by either
   • protonation (to lose water in an S_N1 process),
   • formation of a sulfonate ester (allowing S_N1 or S_N2 processes as the substrate allows) or
   • direct conversion to an organic halide with PCl₃, SOCl₂, PBr₃ or other inorganic acid chlorides.
2. You know how to name ethers as "dialkyl ethers," "alkoxy alkanes," or, where appropriate, as the correct cyclic ether based on the oxetane, furan, pyran or dioxane classes.  You know how to name epoxides as oxiranes or epoxyalkanes (IUPAC) or as "alkene oxides" (common nomenclature).
3. You know that "carbinol" protons on an ether appear at 3.5-4.5 in the ¹H NMR; ether carbons appear at 60-80 in the ¹³C NMR, and that particular features can push these signals upfield (epoxides) or downfield (acetals).  
4. You know the primary means of distinguishing an ether from an alcohol by IR.
5. You recall reactions you have seen before that result in formation of an ether:
• The Williamson ether synthesis (S_N2 attack of an alkoxide on an alkyl halide). (Chapter 7)
• Alkoxymercuration of alkenes (Chapter 11)
• Trapping of alkyl carbocations (formed under S_N1 conditions) by alcohols, including the potential for carbocation rearrangements.(this chapter plus Chapter 8, Chapter 12)
6. You understand the acidity of an alcohol and based on pK_a values can select an appropriate base with which to transform an alcohol into an ether via alkylation.
7. You know how ethers are cleaved by strong hydrohalic acids (HCl, HBr, HI) and can predict the products based on the structure of the two alkyl groups.
8. You remember how mCPBA and MMPP (both peracids) effect transformation of alkenes to epoxides, and the stereochemical outcome.
9. You remember how treatment of a vicinal halohydrin with base forms an epoxide, and the stereochemical outcome.
10. You can write the mechanism for both acid-catalyzed and base-catalyzed ring opening of epoxides.  Based on these two mechanisms, you can correctly predict both the regiochemistry and stereochemistry of the product.
11. You can extend the principles of epoxide ring opening with water to other nucleophiles such as Grignard and organolithium compounds in particular.