We saw earlier how methanol and ethanol are oxidized by liver enzymes to form aldehydes. The two ethyl groups attached to an oxygen atom form an ether molecule. Draw the structure of the alkene formed by the dehydration of cyclohexanol. Can a tertiary alcohol undergo dehydration? This can be seen as a transesterification, acid and some other ester would be needed to form cyclohexylacetate; First, oxidize the alcohol to a ketone, take for example Dess-Martin Periodinane, then use an allyl grignard to form 1-allylcyclohexan-1-ol

Because a variety of oxidizing agents can bring about oxidation, we can indicate an oxidizing agent without specifying a particular one by writing an equation with the symbol [O] above the arrow. Tertiary alcohols (R 3 COH) are resistant to oxidation because the carbon atom that carries the OH group does not have a hydrogen atom attached but is instead bonded to other carbon atoms. The third reaction type—esterification—is covered elsewhere. The carbon-to-hydrogen bonding is easily broken under oxidative conditions, but carbon-to-carbon bonds are not. 5. Describe the result of the oxidation of a secondary alcohol. Tertiary alcohols (R3COH) are resistant to oxidation because the carbon atom that carries the OH group does not have a hydrogen atom attached but is instead bonded to other carbon atoms. Why do tertiary alcohols not undergo oxidation? Secondary alcohols are oxidized to form ketones. Name each reactant and product. Look at conjugated base stability.

Organic Chemistry 32-235 Practice Exam #4 ... (C) 3-hydroxy-5-hexene(D) Isohexen-3-ol (E) 4-hydroxy-1-hexene (A), alcohol is the parent name, taking precedence over alkene. S17.6.1 (a) (b) (c) (d) (e) S17.6.2. 4. The entire OH group of one molecule and only the hydrogen atom of the OH group of the second molecule are removed. OH a) H 2SO 4 heat OH CH 3-CH 2-CH-CH 2-CH 3 b) H 2SO 4 heat Answer OH a) H 2SO 4 heat OH CH 3-CH 2-CH-CH 2-CH 3 b) H 2SO 4 heat CH 3-CH 2-CH=CH-CH 3 + H 2O + H 2O 3-pentanol 2-pentene cyclohexanol cyclohexene 3. Although the participating compounds are complex, the reaction is the same: elimination of water from the starting material. The oxidation reactions we have described involve the formation of a carbon-to-oxygen double bond. The oxidation of isopropyl alcohol by potassium dichromate (K2Cr2O7) gives acetone, the simplest ketone: Unlike aldehydes, ketones are relatively resistant to further oxidation, so no special precautions are required to isolate them as they form. In a reaction, compound W with the molecular formula C4H10O is converted to compound X with the formula C4H8O. Primary and secondary alcohols are readily oxidized. The first step is to recognize the class of each alcohol as primary, secondary, or tertiary. Use [O] above the arrow to indicate an oxidizing agent. Is W oxidized, reduced, dehydrated, or none of these? Show all organic products – if two or more products form, indicate The reaction removes the OH group from the alcohol carbon atom and a hydrogen atom from an adjacent carbon atom in the same molecule: Under the proper conditions, it is possible for the dehydration to occur between two alcohol molecules. Describe the nucleophilic substitution reactions that can be used to prepare alcohols, ethers, thiols, and sulfides.