Download Summary of Alcohol Reactions - Organic Chemistry Cheat Sheet and more Cheat Sheet Organic Chemistry in PDF only on Docsity! Chem 350 Jasperse Ch. 11 Handouts 1 Summary of Alcohol Reactions, Ch. 11. 1 R OH R ONa Acid-Base + HZ ??? + NaZ 1. Deprotonation by a base. 2. Controlled by relative stability of RO versus Z . 3. Consider relative electronegativity and whether either anion is resonance stabilized. 2 R OH R ONa Na • Potassium (K) analogous. • Key way to convert alcohol to alkoxide, reactive as SN2 nucleophile and E2 base. 3 R OH R O R' 1. Na 2. R'-X • Alkoxide formation-SN2 route to ether • The electrophile R'-X must be SN2 reactive, preferably 1º with a good leaving group 4 R H R H O Aldehydes 1º Alcohols Only PCC OH H • Key access to aldehydes, which are useful for more Grignard chemistry. • Note difference between PCC and H2CrO4 • PCC does not react with 2º alcohols very rapidly 5 R R R R OOH H2CrO4 = Na2Cr2O7, H2SO4 or CrO3/H2O Ketones2º Alcohols Only H2CrO4 H • Key access to ketones. • PCC does not react very fast with 2º alcohols 6 R OH O 1º Alcohols Only Acids H2CrO4 R H OH H • Note difference between • PCC and H2CrO4 when reacting with 1º alcohols. 7 R H R OH OO AcidsAldehydes H2CrO4 8 R OH R Br Mech: Be able to draw! 3º alcohols HBr • HI, HCl analogous • Converts alcohol into a bromide that can be used in Grignards, E2 reactions • Cation mechanism • Usually not method of choice for 1º, 2º alcohols Chem 350 Jasperse Ch. 11 Handouts 2 9 R OH R Br 1º or 2º alcohols PBr3 • Converts alcohol into a bromide that can be used in Grignards, E2, SN2 reactions • Inversion of stereochem • Not good for 3º alcohols 10 R OH 1. PBr3 or HBr 2. Mg RMgBr • Quick 2-step conversion of alcohol into a nucleophilic Grignard 11 R OH R I 1º or 2º alcohols P/I2 • Via PI3 12 R OH R Cl 1º or 2º alcohols SOCl2 • Retention of stereo! 13 R OH R OTs TsCl NEt3 • Tosylates are super leaving groups, better even than iodides. • Tosylates are well suited to SN2 and E2 reactions. 14 R R Br HBr • Markovnikov addition 15 R R Br HBr peroxides • anti-Markovnikov addition 16 R H R Br Br2, hv • Radical mechanism, 3º > 2º > 1º 17 R R OH R R H2SO4, heat • Zaytsev elimination
