Chapter 10 -Reaction of Alcohols I. Oxidation-Reduction Oxidation : loss of H2; addition of O or O2; addition of X2 Reduction: addition of H2 or H_; loss of O or O2; addition of X2 II. Oxidation of Alcohols A. Secondary alcohol--------> ketone chromic acid reagent (potassium dichromate and sulfuric mixture) mechanism involves the initial formation of a chromate ester followed by elimination of hydrogen attached to OH carbon and CrO3H B. Primary alcohol 1. all-the way - chromic acid reagent or KMnO4 RCH2OH -------> RCHO --------> RCO2H 2. Stopping at the aldehyde stage - PCC C. Tertiary alcohols - no reaction at normal temperatures used in oxidation D. Biological Oxidation ethanol goes to ethanal in the presence of NADH+ and ADH (alcohol dehydrogenase); NADH+ is converted to NAD. Transfer of a pro-R hydrogen to the front face of the pyridine ring in NADH+ . The process is repeated for the conversion of acetaldehyde to acetic acid. III. Alcohols as Nukes A. Formation of Tosylate esters - read section 10-7. B. Alkoxide formation and subsequent E-2 reactions IV. Alcohols as Electrophiles A. Reaction of Alcohols with HX ROH + HX -------RX + HOH HBr is the most general acid used - Reacts with primary, sec and tert alcohols HCl reacts ok with secondary and tertiary alcohols, but not primary use Lucus reagent to get primary alcohols to react (ZnCl2/ HCl HI gives low yields READ about limitations on p. 446. B. Reaction of Alcohols with PX3 Work best with primary and secondary alcohols SN2 displacement of dihalophosphorus from intermediate - stereochemistry inversion of configuration C. Reaction of Alcohols with SOCl2 - retention of configuration under some conditions. D. Dehydration of alcohols - read p. 450 to 454. E. Unique Reaction of pinnacol ---pinacalone.