<p>Chapter 10</p><p> Classification</p><p> o Alcohols are classified much like alkyl halides - 1°, 2°, and 3°</p><p> Nomenclature</p><p> o Alcohols have precedence over alkenes and alkynes</p><p>. Get to the hydroxyl first!</p><p> You do have to say “1” with straight-chain alcohols</p><p>H O Br (S,E) 4-bromohex-2-en-1-ol</p><p> When the alcohol is the highest-priority group on a cyclic molecule, then the “1” is implied so you leave it off.</p><p>. Don’t worry about the sections naming diols and phenols</p><p> You do need to name diols as “diol,” you just don’t need to call them glycols or anything else weird. </p><p> When you name a cyclic diol, you do need to say the “1”</p><p>O H</p><p>Cl OH</p><p>2-chlorocyclohexan-1,3-diol</p><p> Physical Properties</p><p> o Hydrogen bonding causes higher boiling points</p><p> o Solubility – small alcohols are miscible with water; larger alcohols are not terribly soluble</p><p> Solubility o Smaller alcohols are miscible with water</p><p> o The larger the nonpolar piece, the less soluble the alcohol is in water</p><p> o You know this!</p><p> Acidity</p><p> o pka – 15-18</p><p> o phenol - pka – 10</p><p>. Why? The conjugate base, phenoxide, is resonance stabilized</p><p>H - - O O O O O + H+ - -</p><p> Formation of Alkoxides</p><p> o Acid/base</p><p>. Alcohol + very strong base (NaH, NaNH2) → Alkoxide</p><p> If you just use hydroxide or an alkoxide, you will get an equilibrium mixture.</p><p> The hydroxide or alkoxide is not strong enough to quantitatively deprotonate an alcohol (unless it’s a phenol)</p><p> o Redox</p><p>. Alcohol + alkali metal → Alkoxide</p><p>. This is one of the few times when you see Na or K and it’s significant.</p><p> Synthesis Review</p><p> o SN2</p><p>. -OH added to primary or methyl alkyl halides</p><p>. See Chapter 6 Review</p><p> o SN1 . Water added to secondary or tertiary alkyl halides</p><p>. See Chapter 6 Review</p><p> o Acid-catalyzed hydration of alkenes</p><p>. Markovnikov addition of water with rearrangement</p><p>. See Chapter 8 Review</p><p> o Oxymercuration-demercuration </p><p>. Markovnikov addition of water without rearrangement</p><p>. See Chapter 8 Review</p><p> o Hydroboration-oxidation</p><p>. Anti-Markovnikov addition of water</p><p>. See Chapter 8 Review</p><p> o Addition of OsO4 or KMnO4 to alkenes</p><p>. Syn addition of two hydroxyls</p><p>. See Chapter 8 Review</p><p> o Acid-catalyzed ring-opening of epoxides</p><p>. Results in two hydroxyls added anti to one another</p><p>. See Chapter 8 Review</p><p> o Addition of acetylide ions to carbonyls</p><p>. See Chapter 9 Review</p><p> Grignards/Organometallics</p><p> o Formation of Grignards and alkyl lithiums</p><p>. Magnesium inserts between carbon and halogens</p><p>. Lithium replaces the halogen . This is one time where an sp3-hybridized carbon acts the same as an sp2- hybridized carbon. </p><p> This means that this works on any carbon-halogen bond</p><p>. Solvent</p><p> There cannot be any acidic protons in the solvent, as the Grignard is such a strong base.</p><p> There cannot be any pi bonds in the solvent as those are sites of reactivity that the Grignard will attack.</p><p>. From here on, I will use Grignard to refer to both Grignard reagents and organolithiums, as they do the same things</p><p>. The carbon-metal bond is so strongly polar that it’s fine to think of it as ionic. </p><p> Because of this, it’s often easiest to cross out the Li or MgBr and call the R-group an R-</p><p>- Ex. CH3CH2MgBr CH3CH2MgBr o Grignards as nucleophiles in SN2 reactions</p><p>. Grignards are strong bases/nucleophiles, so they will participate in both </p><p>SN2 and E2 reactions</p><p> SN2 with methyl and primary alkyl halides</p><p>- CH3MgBr Br CH3</p><p> E2 with secondary and tertiary alkyl halides – no point in using this strong of a base o Grignards attacking carbonyls</p><p>. The negatively charged carbon of the Grignard is attracted to the partially positive carbon of the carbonyl . In the following schemes, A and B are just the alkyl pieces attached to the carbonyl-containing molecules and C is the Grignard or other strong nucleophile (such as an acetylide ion)</p><p>. Addition of to ketones and aldehydes</p><p>O 1) C 2) H+ O H A C A B B</p><p>. Addition to esters</p><p>O 1) C 2) H+ OH A C A OB C</p><p>. Addition to Acid Chlorides</p><p>O 1) C 2) H+ O H A C A Cl C o Addition of Grignards to epoxides</p><p>. Grignards (and other strong bases) attack the less substituted side of </p><p> epoxides in an SN2-like mechanism</p><p>O– + O H O H</p><p>R- R R</p>