4 - ALCOHOLS AND PHENOLS

Abstract

This chapter discusses the synthetically useful methods for preparation of alcohols that depend on hydrolysis, condensation, and reduction reactions of carbonyl or alkylene oxide compounds. It also discusses the oxidation reactions. Hydrolysis reactions involving alkyl or activated aryl halides and sulfonates or diazonium compounds afford alcohols in good yields. The products in some cases may be contaminated by olefin by-products. Bucherer reaction of an aromatic amine can be considered a hydrolysis reaction. Hydration of olefins can be considered a hydrolysis reaction because the olefin on reaction with sulfuric acid yields an alkyl sulfuric acid, which on subsequent hydrolysis yields the alcohol. Sulfuric acid adds to olefins in accordance with the Markovnikoff rule. Alkyl halides, aldehydes, ketones, and esters can be converted to alcohols of a higher carbon content by condensation reactions involving the Grignard reagent or a related organometallic. The Friedel–Crafts condensation of ethylene oxide with aromatics gives aryl ethanols in good yields.