Answers_to______the_art_of_writing_reactions_mechanism.pdf

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1、1AnswersToChapter1In-ChapterProblems.1.1.Theresonancestructureontherightisbetterbecauseeveryatomhasitsoctet.1.2.–OOCH+CHCHCH2222COCONMe2NMe2NMe2NMe2NMe2NMe2NNNNNH3CH3CNCH2NCH2H3CH3CthesecondstructureishopelesslystrainedOOChapter121.3.2sp3Osp–sp3sp2OCH3CH3232sp3spNPhNspspspspOPhH3CCH3H3CCH323sp3s

2、p3sp2sp2allsp2spallspsp2F2sp3HspHsp2spOsp2sp2BH2CCH3FFHH1.4.TheOatominfuranhassp2hybridization.Onelonepairresidesintheporbitalandisusedinresonance;theotherresidesinansp2orbitalandisnotusedinresonance.1.5.(a)Noby-products.C(1–3)andC(6–9)arethekeystonumbering.10123O512124OH+9O11H,H2O14613258PhPh97

3、8671113O103H(b)Afternumberingthemajorproduct,C6andBr25areleftover,somakeabondbetweenthemandcallittheby-product.2412131415BrH162115141020O17HN11162425131221O11625181Br919BrBr1Br9N20MeBr8171021821922OMe483734237OMe5OMe6O51.6.(a)MakeC4–O12,C6–C11,C9–O12.BreakC4–C6,C9–C11,C11–O12.(b)MakeC8–N10,C9–C1

4、3,C12–Br24.BreakO5–C6,C8–C9.1.7.PhCºCHismuchmoreacidicthanBuCºCH.BecausethepKbofHO–is15,PhCºCHhasapKa£23andBuCºCHhaspKa>23.Chapter131.8.TheOHismoreacidic(pKa»17)thantheCatotheketone(pKa»20).Becausetheby-productofthereactionisH2O,thereisnoneedtobreaktheO–Hbondtogettoproduct,buttheC–Hbondatotheket

5、onemustbebroken.Chapter14AnswersToChapter1End-Of-ChapterProblems.1.(a)BothNandOinamideshavelonepairsthatcanreactwithelectrophiles.WhentheOreactswithanelectrophileE+,aproductisobtainedforwhichtwogoodresonancestructurescanbedrawn.WhentheNreacts,onlyonegoodresonancestructurecanbedrawnfortheproduct.

6、EEOOOreactiononOreactiononNRRRRNRNRNRRER(b)EstersarelowerinenergythanketonesbecauseofresonancestabilizationfromtheOatom.Uponadditionofanucleophiletoeitheranesteroraketone,atetrahedralintermediateisobtainedforwhichresonanceisnotnearlyasimportant,andthereforethetetrahedralproductfromtheesterisnear

7、lythesameenergyasthetetrahedralproductfromtheketone.Asaresultitcostsmoreenergytoaddanucleophiletoanesterthanitdoestoaddonetoaketone.(c)Exactlythesameargumentasin(b)canbeappliedtotheacidityofacylchloridesversustheacidityofest