1559T_ch19_344-35710/17/0513:51Pa9e347 ⊕ EQA Solutions to Problems.347 nother due to electro an派o，或itcul toe可 bad leaving groups Nevertheless.LiAH s capable ofad cohol. te.formally.n aluminum oxide anion leav 19-12.a-Bromination A useful method of -substitution in carboxylic acids is via the -bromo derivative.synthesized using the Hell- Volhard-Zelinsky reaction. Solutions to Problems 23.(a)2-Chloro-4-methylpentanoic acid:(b)2-ethyl-3-butenoic acid (e)E-2-bromo-3.4-dimethyl-2-pentenoic acid (d)cyclopentylacetic acid: (e)trans-2-hydroxycyclohexanccarboxylic acid: (f)E-2-chlorobutenedioic acid: (g)2.4-dihydroxy-6-methylbenzoic acid: (h)1.2-benzenedicarboxylic acid:(i) COOH (k)O H CH.CCOOH CH CH3- -H COOH COOH CO2H CO2H COOH CH COOH CH2OH CHO 24. > The order is the same for both boiling point and solubility in water.The acid has the most hydrogen- bonding capability and will have the highest boiling point (249C)because of its hydrogen-bonde d th quemnater becase they canbyo 25.(a)Order is as written:(b)order is reverse of that given: (c)CHCH,CHCICO,H>CH CHCICH CO,H>CICH CH,CH,CO,H: (d)order is as written:(e)2.4-dinitro>4-nitro>unsubstituted>4-methoxybenzoic Solutions to Problems • 347 the elimination is hard to do. More specifically, (1) it is difficult to add one anion to another due to electro￾static repulsion and (2) oxide anions are extremely bad leaving groups. Nevertheless, LiAlH4 is capable of ad￾dition to RCOO, and the product of addition can go on to eliminate, formally, an aluminum oxide anion leav￾ing group. The product of an acid LiAlH4 is a primary alcohol. 19-12.
-Bromination A useful method of
-substitution in carboxylic acids is via the
-bromo derivative, synthesized using the Hell￾Volhard-Zelinsky reaction. Solutions to Problems 23. (a) 2-Chloro-4-methylpentanoic acid; (b) 2-ethyl-3-butenoic acid (c) E-2-bromo-3,4-dimethyl-2-pentenoic acid; (d) cyclopentylacetic acid; (e) trans-2-hydroxycyclohexanecarboxylic acid; (f) E-2-chlorobutenedioic acid; (g) 2,4-dihydroxy-6-methylbenzoic acid; (h) 1,2-benzenedicarboxylic acid; (i) H2NCH2CH2CH2COOH (j) (k) (l) (m) (n) 24. The order is the same for both boiling point and solubility in water. The acid has the most hydrogen￾bonding capability and will have the highest boiling point (249°C) because of its hydrogen-bonded dimer formation. The alcohol, which can also hydrogen bond, is next (205°C), the polar aldehyde third (178°C), and the nearly nonpolar hydrocarbon last (115°C). Solubilities follow similar considerations, except that the acid and alcohol are quite similar in water solubility because they can both hydrogen bond with H2O. 25. (a) Order is as written; (b) order is reverse of that given; (c) CH3CH2CHClCO2H  CH3CHClCH2CO2H  ClCH2CH2CH2CO2H; (d) order is as written; (e) 2,4-dinitro  4-nitro  unsubstituted  4-methoxybenzoic COOH  CH2OH  CHO  CH3 CO2H CO2H C COOH H C CH3 COOH CH O H COOH COOH CH3 CH3 H O B CH3CCOOH 1559T_ch19_344-357 10/17/05 13:51 Page 347