Important Concepts
1. Alcohols are alkanols in IUPAC nomenclature. The stem containing the functional group gives
the alcohol its name. Alkyl and halo substituents are added as prefixes.
2. Like water, alcohols have a polarized and short O – H bond. The hydroxy group is hydrophilic
and enters into hydrogen bonding. Consequently, alcohols have unusually high boiling points
and, in many cases, appreciable water solubility. The alkyl part of the molecule is hydrophobic.
3. Again like water, alcohols are amphoteric: They are both acidic and basic. Complete deprotonation to an alkoxide takes place with bases whose conjugate acids are considerably weaker than the alcohol. Protonation gives an alkyloxonium ion. In solution, the order of acidity is primary .secondary .tertiary alcohol. Electron-withdrawing substituents increase the acidity (and reduce the basicity).
4. The conversion of the electrophilic alkyl group in a haloalkane, Cδ+ − Xδ-, into its nucleophilic analog in an organometallic compound, Cδ- − Mδ+, is an example of reverse polarization.
5. The carbon atom in the carbonyl group, C = O, of an aldehyde or a ketone is electrophilic and therefore subject to attack by nucleophiles, such as hydride in hydride reagentsor alkyl in organometallic compounds. Subsequent to aqueous work-up, the products of such transformations are alcohols.
6. The oxidation of alcohols to aldehydes and ketones by chromium(VI) reagents opens up important
synthetic possibilities based on further reactions with organometallic reagents.
7. Retrosynthetic analysis aids in planning the synthesis of complex organic molecules by identifying
strategic bonds that may be constructed in an efficient sequence of reactions.
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