Chapter 88.1 Name the following compounds: (a) CH3 CH3CHC CH3 CCHCH3 2,5-dimethyl-3-hexyne (b) CH3 HC CCCH3 CH3 3,3-dimethyl-1-butyne (c) H3CHC CHCH CHC CCH3 2,4-octadiene-6-yne (d) H 3C H3CH2CCC H 3C CCH2CH2CH3 3,3-dimethyl-4-octyne (e) H3C H3CH2CCC H3C CH3 CCHCH3 2,5,5-trimethyl-3-heptyne (f) 6-isopropyl-cyclodecyne 8.2 There are seven isomeric alkynes with the formula C6H10. Draw and name them. Solution: 1-Hexyne 2-Hexyne 3-Hexyne 3-methyl-1-pentyne 4-methyl-1-pentyne 4-methyl-2-pentyne 3,3-dimethyl-1-butyne 8.3 What products would you expect from the following reactions? (a) H2 C H3 C C H2 C CH + H2 C Cl C H2 C CH Cl 2Cl 2 H 3C Cl (b) Cl C CH + C C HBr C CH2 Br (c) H2 C H 3C C H2 H2 C CH3 + C 4H 9 HBr Br C H C CH3 8.4 What product would you obtain by hydration of the following alkynes? 7 How would you prepare the following carbonyl compounds starting from an alkyne? .(a) hydration C 3H 7 C C C3H 7 C3H 7 C O (b) H2 C C3H 7 3HC H3 C CH H2 C hydration C C C 3H 7 H3 C 3HC CH H2 C C O C C 3H 7 H2 8.6 What alkyne would you start to prepare each of the following compounds by a hydroboration / oxidation reaction? O CH2 CH CH3 O CH3CHCH2CCHCH3 (a) Solution: CH C (b) CH3 CH3 CH3CHC (a) (b) CCHCH3 CH3 8.5 What alkynes would you start with to prepare the following ketones? O O (a) CH3CH2CH2CCH3 (b) CH3CH2CCH2CH3 Solution: (a) CH3CH2CH2C CH (b) CH3CH2C CCH3 8. 9 Propose structures for alkynes that give the following products on oxidative cleavage by KMnO4: (a) CO2H + CO2 .8 Using any alkyne needed. H3O O O 1.NH3 (b) H2 Lindlar catalyst (c) H2 Lindlar catalyst 8.H2O2 / NaOH 8. how would you prepare the following alkenes? (a) trans-2-Octene (b) cis-3-Heptene (c) 3-Methyl-1-pentene solution: (a) Li.BH3 2.Br O O solution: Br Br HgSO4. Answer: (a) H3CH2 CH2CC H3CH2CH2C CH CH Br (b) Na+ -C≡CH (pKa of C2H2 = 25) (d) NaOCH3 (pKa of CH3OH = 15. list both.6) CH3 CH2CH2CH3 C C CH3 3HCC Br (b) H3C H3CHC C C CH2CH3 CCH3 C H3C H3CHC C CH Br CH2CH3 CH C BrCH3 (c) 8. Which of the following bases is strong enough to deprotonate acetone? (a) KOH (pKa of H2O = 15.4) Solution: (b) Because pKa (C2H2) > pKa (CH3COCH3) 8. You’ll have to carry out more than one . If two routes look feasible.3.10 The pKa of acetone. and any other reagents needed? This problem can’t be worked in a single step.12 How would you prepare cis-2-butene starting from propyne. is 19.7) (c) NaHCO3 (pKa of H2CO3 = 6. CH3COCH3.(b) 2CH3(CH2)7CO2H + HO2C(CH2)7CO2H Solution: The structure is: (a) (b) CH3(CH2)7C≡C(CH2)7C≡C(CH2)7CH3 8. an alkyl halide.11 Show the terminal alkyne and alkyl halide from which the following products can be obtained. how would you synthesize the following compounds? (a) Butanoic acid Solution: (a) O (b) cis-4-Octene (c) 4-Bromooctane (d) 4-Octanol (4-hydroxyoctane) (e) 4.reaction. Answer: H3CC CH NaNH2 NH3 H2 BrCH3 THF HC H3C H3CC CCH3 CH CH3 H3CC CCH3 Lindar catalyst 8.5-Dichlorooctane KMnO4 H3O (b) H2 Lindler catalyst 2 OH (c) H2 Lindler catalyst HBr.13 Beginning with 4-octyne as your only source of carbon and using any inorganic reagents necessary. ether Br (d) . OHOH (e) H2 Lindler catalyst X2 CH2Cl2 Cl Cl 8.14 Beginning with acetylene and any alkyl halides needed.BF3 .2-Dimethylhexane (d) 2-Heptanone NaNH2 Na C CH CH3 CH2 CH2CH2CH2CH2CH2CH2Br 2H2 Pd/C (b) . THF 2.H2 O2 .H2 Lindler catalyst 1. how would you synthesize the following compounds? (a) Decane (c) Hexanal Solution: (a) (b) 2. and predict the products of their reaction with (i) H2 in the presence of a Lindlar catalyst and (ii) H3O+ in the presence of HgSO4: (a) HC C C H2 H3C C H2C CH3 CH3 H3C (b) CH3 HC C H2 C C CH2 CH H3C CH3 Solution: .NaNH2 Na C CH (CH3)3CCH2CH2Br 2H2 Pd/C (c) NaNH2 Na C CH CH3CH2CH2CH2Br 1.15 Name the following alkynes.H2O2 O (d) NaNH2 Na C CH CH3CH2CH2CH2CH2Br H2 SO4.BH3 2. H2O HgSO4 O 8. 17 How would you prepare the following substances.16 From what alkyne might each of the following substances have been made? (a) CH3 CH H3C C H2 H2 C C H O H2 C (b) H2 C CH3 H C C H2 Cl C Cl CH3 SO Hg H 2 i /L 4 rC la nd /H 3 O at + O H H2 C C H O gS 4 /H 3 O + O Solution: (a) is from CH3 CH H3C H2C C CH H2 C H2 C CH3 H C C H2 H2 C C H C CH 4-Methyl-pentyne and (b) is from 1-Ethynyl-2-methyl-cyclohexane 8. starting from any compounds having four carbons or fewer? HO CH2 C H2 CH HC C H2 (a) H3 C .H 2 /L in dl ar Ca t 8. 8. CH3 CH3 CH2C a.18 The following cycloalkyne is too unstable to exist. H2C C H2 CH2 Solution: It’s not possible to form a small ring containing a triple bond because the angle strain that would result from bending the bonds of an SP-hybridized carbon to form a small ring is too great. CCCH3 CH3 CH3C CCH2C CH3 CCH2CH3 CH3 c. b. CH3CH CC CCHCH3 . Explain. H2O HgSO4 H2C C H2 C C H2 H C CH3 H2C C Solution: 8.19 Give IUPAC names for the following compounds.HO H C C H2 O H2 C C C H2 H CH3 OH CH CH2 Zn(Cu) Ether H 3C CH C H2 HC CH2 C H2 Solution: H3C H2C C (b) O H2 C C C H2 H CH H2SO4. 8-decatriyne c. e.5-Octadiyne c.3-Dimethyl-4-octyne .6-Diethyl-2-methyl-4-octyne 8.5-Heptadien-1-yne f.3-Hexadiene-5-yne f.4-dimethyl-1-nonen-6-yne g. 2.6-Dimethyl-2-heptene-4-yne d. 3-Ethyl-5-methyl-1.3-Dimethyl-4-octyne b.6. 3. 3.5. H2 C CCCH2C CH3 CHCH CH CHC CH CH2CH3 CH3CH2 CHC f.4-Dimethylcyclodecyne e.2-Dimethyl-3-hexyne b.5-hexadiyne e.2. 3. 5-tert-Butyl-2-methyl-3-octyne Solution: a.5-Tetramethyl-3-hexyne d.CH3 HC d.20 Draw structures corresponding to the following names: a. 3. 3. 3. 3. 2. 3-sec-Butyl-1-heptyne h. 2.3-Dimethyl-1. 3-Chloro-4. 1. Solution: CH2CH3 CCHCHCH3 CH3 a. 3. 3-Ethyl-5-methyl-1.6-Dimethyl-2-heptene-4-yne d.5-Heptadien-1-yne Cl f. 3.4-Dimethylcyclodecyne e. 3-sec-Butyl-1-heptyne .b.4-dimethyl-1-nonen-6-yne g.8-decatriyne c. 3-Chloro-4. 3.6. 5E. Name them according to IUPAC rules.21 The following two hydrocarbons have been isolated from various plants in the sunflower family.11-Tridecatetraen-7. Predict the products of the following reactions. H H2. Pd/C A H2/Lindlar SOLUTION: A: H2 C C H2 H2 C CH3 B B: . (a) H3C C H C H C C C C C H C H C H C H C H CH2 (b) H3C C C C C C C C C C C C H CH2 SOLUTION: (a) (b) (3E. 9.22. 9-diyne.h. 11E)-1.5. 11-pentayne 8.3. 5. 5-tert-Butyl-2-methyl-3-octyne 8. 1-Tridecene-3. 7. HgSO4 Solution: b) 1 equiv Cl2 d) NaNH2. in NH3. 8. Solution: a) c) e) 4 degrees of unsaturation are present. the CH3Br f)2 equiv HCl HCl a) 1-hexyne Cl2 Cl Cl b) 1-hexyne H2 Lindlar Catalyst Cl H c) 1-hexyne H H NaNH2 CNa CH3Br d) 1-hexyne NH3 . 1 equivalent of H2 is absorbed. a) How many degrees of unsaturation are present in the unknown? b) How many triple bonds are present? c) How many double bonds are present? d) How many rings are present? e) Draw a structure that fits the data. etc. 1 double bond is present. Lindlare catalyst e) H2O. H2SO4.H C C H H C CH2 8. On catalytic hydrogenation over the Lindlar catalyst..24 Predict the products from reaction of 1-hexyne with the following reagents: a) 1 equiv HBr c) H2.. d) 1 ring is present. The possible structure can be: b) 1 triple bond is present. On hydrogenation over a palladium catalyst. 3 equivalents of H2 are absorbed.23 A hydrocarbon of unknown structure has the formula C8H10. HgSO4. (d) BH3 in THF.NH3 CH (b) . (e) H2O. (c) 1 equiv Br2. Lindlar catalyst. (c) C4H9 Br . then H2O2. H2SO4. O (b) C4H9 H . (d) Li in NH3. Pd/C catalyst. Br H3C H C3H7 H3C (c) H3C and H3C O Br H H3C (d) H C3H7. (b) 1 equiv HBr. (c) Excess HBr. .O H2SO4.25 Predict the products from reaction of 5-decyne with the following reagents: (a) H2..BH3. (b) etc. (e) H2O. Solution: H H H C4H9 Br C4H9 O (a) C4H9 C4H9 C4H9.H2O2 O CH3CH2CH2 CH2CH2CH2 CH (a) Br CH2 C NaNH2.26 Predict the products from reaction of 2-hexyne with following reagents: (a) 2 equiv Br2. C4H9 (e) C4H9. (f) Excess H2. HgSO4 Solution: Br H3C Br H3C H H3C C3H7 C3H7 Br H Br Br C3H7 H Br H + Br C3H7 Br H (a) . (b) Li in NH3.H2O HgSO4 e) 1-hexyne Cl 2HCl f) 1-hexyne Cl 8. (d) C4H9 C4H9. OH-. H2SO4.THF 2. (e) C3H7 and O C3H7 8.27 Predict the products of the following reactions: CH3CH2CH2CH2 CH2C CH 1. (f) C4H9 8. 29 How would you carry out the following reactions? .Br Br CH3 NaNH2. and write the reactions. Oxidation of A with KMnO4 gives a mixture of acetic acid (CH3CO2H) and the tricarboxylic acid E. C and D.C9H18 . On treatment of A with aqueous H2SO4 in the presence of mercury(II). Solution: H2 C C C CH3 H2 H2 O C C C A B H2 H2 H2 C C C CH3 H2 O H2 C C C CH3 C CH3 D E H HOOCH2C C CH2COOH CH2COOH H2 C C C CH3 H2 Pd/C H2 H2 H2 C C C CH3 H2 H2 O C C C H2 O H2 C C C CH3 (1) (2) H2 C C C CH3 mercury(II) H2SO4 CH3 + (3) H2 C C C CH3 KMnO4 H HOOCH2C C CH2COOH CH2COOH + CH3COOH 8. two isomeric ketones.NH3 C CH (c) 8. Propose structure for compounds A-D.28 Hydrocarbon A has the formula C9H12 and absorbs 3 equivalents of to yield B.when hydrogenated over a Pd/C catalyst. are produced. KOH. BH3 2. Li. Br2 2.O (a) H3CH2CC CH H2SO4. KOH. There is no one-step method for doing an alkene inversion. KOH. Br2 2.30 Occasionally. ethanol 3. ethanol 3. NH3 cis-5-Decene (b) cis-5-Decene trans-5-Decene 8. chemists need to invert the stereochemistry of an alkene. that is. How would you carry out the following reactions? (a) trans-5-Decene 1.31 Propose structures for hydrocarbons that give the following products on oxidative cleavage by KmnO4 or O3 (a) CO2 + CH3(CH2)5CO2H CO 2 H CH3CO 2H (b) + . but the transformation can be carried out by combining several reactions in the proper sequence. H2O HgSO4 1. ethanol CH3 CH2 CH2CH2C CH 8. Lindlar catalyst 1. or vice versa. H2O2 CH H3CH2C CCH3 (b) H3CH2 CC CH CH3CH2CH2CHO (c) C C C CH3 NaNH2 CH3Br H C CCH3 (d) H H2 Lindlar catalyst CH3 (e) H3CH2CC CH KMnO4 CH3CH2CO2H (f) CH3CH2 CH2 CH2CH CH2 1. Br2 2. to convert a cis alkene to trans alkene. H2 . (c) HO2(CH2)8CO2H (d) CH3CHO + CH3COCH2CH2CO2H + CO2 (e) OHCCH2CH2CH2CH2COCO2H + CO2 Solution: (a) (b) (c) (d) (e) 8. How would you carry them out? (a) CH3CH2 CH2C CH CH3 CH2CH2CHO (B) H CH2CH3 (CH3)2CHCH2C CH (H3C)2 HCH2C H Solution: (a) H2 Lindlar catalyst 1. Zn/H3 O O .32 Each of the following syntheses requires more than one step. O3 2. ? CHO Solution: OH BH3 H2O2/OHPCC CH2Cl2 CHO 8.(b) (CH3 )2CHCH2C CH NaNH2 (CH3)2CHCH2 C Li NH3 CNa H CH3CH2 Br CH2CH3 (CH3)2 CHCH2C CCH2CH3 (H3C) 2HCH2C H 8.33 How would you carry out the following transformation? More than one step is needed. .35 How would you carry out the following transformation? More than one step is needed.34 How could you carry out the follow conversion? More than one step is needed. H C H H2C H3C CH2 H C H2 H CH3 H H2 + C CH3 H C H H2C H3C CH2 H C H2 H CH3 8. 36 Synthesize the following compounds using 1-butyne as the only source of carbon. along with any inorganic reagents you need. (a) 1. 1. 2-Tetrachlorobutane Solution: Cl HC C CH2 CH3 CH2CH3 C H C Cl Cl Cl C Cl CH2 CH3 Cl2 CH2Cl2 Cl2 CH2Cl2 H C Cl (b) 1.Br Br Br2 CH2Cl2 KOH Ethenal C CH C KNH2 C K CH3Br Li NH3 8. 2. More than one step may be needed. 1-Dichloro-2-ethylcyclopropane Solution: H HC C H2 C CH3 H C H C CH2CH3 Cl Cl C H2C CH CH2 CH3 H2 Lindlar catalyst CHCl3 KOH (c) Butanal Solution： . (a) CH3CH2CH2C CH (b) CH3CH2C CCH2CH3 (c) (CH3)2CHCH2CH CH2 (e) CH3CH2CH2CH2CH2CHO O (d) CH3CH2CH2CCH2CH2CH2CH3 HC CH Solution: (a) (b) HC CH NaNH2 NH3 NaNH2 NH3 HC C Na CH3CH2CH2Br THF CH3CH2CH2C CH HC C Na CH3CH2Br THF CH3CH2 C CH CH3CH2Br NaNH2 CH3CH2C CCH2 CH3 CH3CH2C C Na NH3 THF (c) HC CH NaNH2 NH3 HC C Na (CH3 )2CHCH2Br (CH3)2CHCH2C CH H2 (CH3)2CHCH2CH CH2 Lindlar catalyst (d) NaNH2 NaNH2 CH2CH2CH2Br CH3CH2CH2Br HC C Na CH3CH2 CH2C C Na CH3CH2CH2C CH NH3 NH3 THF THF O H2 SO4. H2 O2. THF 2.38 How would you carry out the following reactions to introduce deuterium into organic molecules? (a) D H3CH2CC CCH2CH3 ? C C2H5 C C2H5 D (b) ? H3CH2CC CCH2CH3 D C C2 H5 C D C2H5 (c) ? H3CH2CH2CC CH H3CH2CH2CC CD (d) .H2O CH3CH2 CH2CCH2CH2CH2CH3 CH3CH2CH2 C CCH2CH2CH3 HgSO4 HC CH (e) HC CH NaNH2 CH3CH2CH2CH2Br 1.BH3 HC C Na CH3CH2 CH2CH2C CH NH3 2.H HC C CH2 CH3 H C C CH2CH3 H2 Lindlar catalyst H 1.37 How would you synthesize the following compounds from Acetylene and any alkyl halides with four or fewer carbons? More than one step may be required.H2O 2 THF CH3CH2CH2 CH2CH2CHO 8. BH3. OH- OH H C H H C H CH2 CH3 8. . What is the IUPAC name for muscalure? cis.39 How would you prepare cyclodecyne starting from acetylene and any alkyl halide needed? Solution: H H + 2 NaNH2 NH3 Na Na THF + I I 8.C CH ? DC CD2 Solution: D CH3CH2C CCH2CH3 D D2 Lindlar catalyst C2H5 C2H5 CH3CH2C CCH2CH3 Li. Propose a synthesis of muscalure starting from acetylene and any alkyl halides needed.40 The sex attractant given off by the common housefly is an alkene named muscalure.ND3 D C2H5 C2H5 D Na+NH2H3CH2CH2CC CH H3CH2CH2CC C Na+ D2O H3CH2CH2CC CD NH3 CD C CD CH C C + - CD2 Na NH2 NH3 C D2O D2 Lindlar catalyst 8.H3C(H2C)7HC CH(CH2)12CH3 Solution: The IUPAC name for muscalure is cis-9-tricosene. compound A gave. only two products are formed: oxalic acid (HO2CCO2H) and succinic acid (HO2CCH2CH2CO2H). B. C. among other things. Slution: . On ozonolysis .Give the structure of A. On ozonolysis. and propose a structure for A. Solution: A: B: C: 8. Write the reactions. On treatment with. It absorbs 8 equivalents of H2 on catalytic reduction over a palladium catalyst.42 Hydrocarbon A has the formula C12H8.NaNH2 H C C H H3 C(H2C)7 Br H3C(H2C)7 C C H NaNH2 H3C(H2C)12 Br H3C(H2C)7 C H C (CH2) 12CH3 H2 Lindlar H3C(H2C)7 C C (CH2) 12CH3 H 8.41 Compound A (C9H12) absorbed 3 equivalents of H on catalytic reduction over a palladium catalyst to give B (C9H18). a ketone that was identified as cyclohexanone. gave C (C10H14) . Na+ C CH + C R R C CH C R R 2.44 Organometallic reagents such as sodium acetylide undergo an addition reaction with ketones. H3O How might you use this reaction to prepare 2-methyl-1.43 Identify the reagents a-c in the following scheme: a b c H H ` Solution: 1. NaNH2. CH3CH2Br H2 / Lindlar Cat CH2I2 / Zn(Cu) H H 8. give OH alcohols: O 1. the starting material used in the manufacture of synthetic rubber Solution： .8H2 Pd/C cyclododecane O O3 O C OH + 2 HO O C CH2CH2 O C 2 HO C 8.3-butadiene. NH3 2. and we can get the solultion t the . CH3(CH2)16CO2H.45 Erythrogenic acid. 5 equivalents of H2 are absorbed. azelaic acid . and there is no rings in the molecular. oxalic acid. H3 O + CH OH H2 SO4. is an acetylenic fatty acid that turns a vivid red on exposure to light. Na+ C 2. O3 . and suggest a way to tell them apart by carrying out some simple reactions. HO2C (CH2)7CO2H. Draw two possible structures for erythrogenic acid. On catalytic hydrogenation over a palladium catalyst. Second we can think about the products after it is treated with problem. and the aldehyde acid OHC(CH2)4CO2H. Solution The problem can be described as following illustration: O H O 5H2 O3 Zn H3+O O 16 C H C C O HO O HO OH OH O H2 C OH O H2 C 4 C18H26O2 C18H36O2 H2 C H3C C O OH 7 OH And first we can predict the unsaturated degree of starting material by the fact that it can absorb 5 H2 and form a carboxylic acid. Ozonolysis of erythrogenic acid gives four products: formaldehyde. is produced. So The molecular has 5 double bonds or 1 triple bond and 3 double bonds or 2 triple bonds and 1 double bond besides a C=O bond. HO2CCO2H.O 1. C18H26O2. CH2O. H2O THF H2 Lindlar catalyst 8. and stearic acid. However. STEP1 Treat the SM with Lindlar catalyst. STEP2 Treat the product get from the step with O3 . HCHO H O HO C C H C H H2 C C 7 H C H H2 C C O3 H HC C O H Zn H3O HC O H2 C O HO C H2 C O CH O CH 4 4 7 O CH .H O HO C C C H2 C C C H2 C C H C 7 H 4 H O HO C H2 C C C C C H2 C CH C 7 H 4 You can see two possible starting materials according to the problem exactly. At last we can tell them apart easily. we can tell them apart from each other by following method. and then we can get the product only contains double bond but no triple bond.H3O+ and Zn and then we can get the products following. STEP3 Analyze the products and you can find the differences written following between the different SMs . HCHO H O HO C H2 C C 7H C H C H C H H2 C CH C H Zn H O 3 O3 HO O HC H2 C O C O HO C H2 C O C OH O CH O CH 4 4 7 8. 8. For example: O Br2 . To what reaction of alkenes is the process analogous? Solution: H O H H Br Br O Br H H Br H O H O H H O Br rearrangement Br The mechanism here is just like the halohydrin of alkene.47 A cumulene is a compound with three adjacent double bonds.46 Terminal alkynes react with Br2 and water to yield bromo ketones. H2O CH2Br Propose a mechanism for the reaction. Draw an orbital picture of cumulene. What kind of hydridization do the two central carbon atoms have? What is the geometric relationship of the substituents on one end to the substituents on the other end? What kind of isomerism . O H3C C CH3 D3O+ D3C O C CD3 Hexadeuterioacetone Acetone Solution: O C H3C CH2 H H3C O H C CH2 D3O+ H3C OH C CH2 D …… D3C O C CD3 . 8.is possible? R 2C Solution: C C CR 2 (a) They are sp hybridized. (c) Stereoisomers. R R C C C C R R (b) The geometric relationship of the substituents on one end to the substituents on the other end is cis and trans. and then propose a mechanism for this deuterium incorporation. all the hydrogens in acetone are exchanged for deuterium. Review the mechanism of alkyne hydration. This is.48 Reaction of acetone with D3O+ yields hexadeuterioacetone.