CHE-300Review nomenclature syntheses reactions mechanisms

Alkanes Alkyl halides Alcohols Ethers Alkenes conjugated dienes Alkynes Alicyclics Epoxides

Alkanes Nomenclature Syntheses 1. reduction of alkene (addition of hydrogen) 2. reduction of an alkyl halide a) hydrolysis of a Grignard reagent b) with an active metal and acid 3. Corey-House Synthesis Reactions 1. halogenation 2. combustion (oxidation) 3. pyrolysis (cracking)

Alkanes, nomenclature CH 3 CH 3 CH 2 CH 2 CH 2 CH 2 CH 3 CH 3 CHCH 2 CH 2 CH 3 (n-hexane) (isohexane) n-hexane2-methylpentane CH 3 CH 3 CH 3 CH 2 CHCH 2 CH 3 CH 3 CCH 2 CH 3 (no common name) CH 3 3-methylpentane (neohexane) 2,2-dimethylbutane CH 3 CH 3 CHCHCH 3 CH 3 (no common name) 2,3-dimethylbutane

Alkanes, syntheses 1. Addition of hydrogen (reduction). | | | | — C = C — + H 2 + Ni, Pt, or Pd  — C — C — | | H H Requires catalyst. CH 3 CH=CHCH 3 + H 2, Ni  CH 3 CH 2 CH 2 CH 3 2-butene n-butane

2.Reduction of an alkyl halide a) hydrolysis of a Grignard reagent (two steps) i) R—X + Mg  RMgX (Grignard reagent) ii) RMgX + H 2 O  RH + Mg(OH)X SB SA WA WB CH 3 CH 2 CH 2 -Br + Mg  CH 3 CH 2 CH 2 -MgBr n-propyl bromiden-propyl magnesium bromide CH 3 CH 2 CH 2 -MgBr + H 2 O  CH 3 CH 2 CH 3 + Mg(OH)Br propane

b)with an active metal and an acid R—X + metal/acid  RH active metals = Sn, Zn, Fe, etc. acid = HCl, etc. (H + ) CH 3 CH 2 CHCH 3 + Sn/HCl  CH 3 CH 2 CH 2 CH 3 + SnCl 2 Cl sec-butyl chloriden-butane CH 3 CH 3 CH 3 CCH 3 + Zn/H +  CH 3 CHCH 3 + ZnBr 2 Br tert-butyl bromideisobutane

3. Corey-House Synthesis CH 3 CH 3 CH 3 CH 3 CH-Br + Li  CH 3 CH-Li + CuI  (CH 3 CH) 2 -CuLi isopropyl bromide CH 3 CH 3 (CH 3 CH) 2 -CuLi + CH 3 CH 2 CH 2 -Br  CH 3 CH-CH 2 CH 2 CH 3 2-methylpentane (isohexane) mechanism = S N 2 Note: the R´X should be a 1 o or methyl halide for the best yields of the final product.

Alkanes, reactions 1. Halogenation R-H + X 2, heat or hv  R-X + HX a) heat or light required for reaction. b) X 2 : Cl 2 > Br 2  I 2 c) yields mixtures  d) H: 3 o > 2 o > 1 o > CH 4 e) bromine is more selective f) free radical substitution

CH 3 CH 2 CH 2 CH 3 + Br 2, hv  CH 3 CH 2 CH 2 CH 2 -Br 2% n-butanen-butyl bromide + CH 3 CH 2 CHCH 3 98% Br sec-butyl bromide CH 3 CH 3 CH 3 CHCH 3 + Br 2, hv  CH 3 CHCH 2 -Br <1% isobutane isobutyl bromide + CH 3 CH 3 CCH 3 99% Br tert-butyl bromide

Alkyl halides nomenclature syntheses 1. from alcohols a) HX b) PX 3 2. halogenation of certain alkanes 3. addition of hydrogen halides to alkenes 4. addition of halogens to alkenes 5. halide exchange for iodide reactions 1. nucleophilic substitution 2. dehydrohalogenation 3. formation of Grignard reagent 4. reduction

Alkyl halides, nomenclature CH 3 CH 3 CH 3 CHCH 2 CHCH 3 CH 3 CCH 3 Br I 2-bromo-4-methylpentanetert-butyl iodide 2-iodo-2-methylpropane 2 o 3 o CH 3 Cl-CHCH 2 CH 3 sec-butyl chloride 2-chlorobutane 2 o

Alkyl halides, syntheses 1. From alcohols a)With HX R-OH + HX  R-X + H 2 O i) HX = HCl, HBr, HI ii) may be acid catalyzed (H + ) iii) ROH: 3 o > 2 o > CH 3 > 1 o (3 o /2 o – S N 1; CH 3 /1 o – S N 2) iv) rearrangements are possible except with most 1 o ROH

CH 3 CH 2 CH 2 CH 2 -OH + NaBr, H 2 SO 4, heat  CH 3 CH 2 CH 2 CH 2 -Br n-butyl alcohol (HBr)n-butyl bromide 1-butanol1-bromobutane CH 3 CH 3 CH 3 CCH 3 + HCl  CH 3 CCH 3 OH Cl tert-butyl alcoholtert-butyl chloride 2-methyl-2-propanol2-chloro-2-methylpropane CH 3 -OH + HI, H +,heat  CH 3 -I methyl alcohol methyl iodide methanol iodomethane

…from alcohols: b) PX 3 i) PX 3 = PCl 3, PBr 3, P + I 2 ii) ROH: CH 3 > 1 o > 2 o iii) no rearragements CH 3 CH 2 -OH + P, I 2  CH 3 CH 2 -I ethyl alcohol ethyl iodide ethanol iodoethane CH 3 CH 3 CH 3 CHCH 2 -OH + PBr 3  CH 3 CHCH 2 -Br isobutyl alcohol isobutyl bromide 2-methyl-1-propanol 1-bromo-2-methylpropane

2.Halogenation of certain hydrocarbons. R-H + X 2, Δ or hν  R-X + HX (requires Δ or hν; Cl 2 > Br 2 (I 2 NR); 3 o >2 o >1 o )  yields mixtures!  In syntheses, limited to those hydrocarbons that yield only one monohalogenated product. CH 3 CH 3 CH 3 CCH 3 + Cl 2, heat  CH 3 CCH 2 -Cl CH 3 CH 3 neopentane neopentyl chloride 2,2-dimethylpropane 1-chloro-2,2-dimethylpropane

5.Halide exchange for iodide. R-X + NaI, acetone  R-I + NaX  i) R-X = R-Cl or R-Br ii) NaI is soluble in acetone, NaCl/NaBr are insoluble. CH 3 CH 2 CH 2 -Br + NaI, acetone  CH 3 CH 2 CH 2 -I n-propyl bromide n-propyl idodide 1-bromopropane 1-idodopropane iii) S N 2 R-X should be 1 o or CH 3

Reactions of alkyl halides: 1.Nucleophilic substitution  Best with 1 o or CH 3 !!!!!! R-X + :Z -  R-Z + :X - 2.Dehydrohalogenation R-X + KOH(alc)  alkene(s) 3.Preparation of Grignard Reagent R-X + Mg  RMgX 4.Reduction R-X + Mg  RMgX + H 2 O  R-H R-X + Sn, HCl  R-H

1. Nucleophilic substitution R-X + :OH -  ROH + :X - alcohol R-X + H 2 O  ROH + HX alcohol R-X + :OR´ -  R-O-R´ + :X - ether R-X + - :C  CR´  R-C  CR´ + :X - alkyne R-X + :I -  R-I + :X - iodide R-X + :CN -  R-C  N + :X - nitrile R-X + :NH 3  R-NH 2 + HXprimary amine R-X + :NH 2 R´  R-NHR´ + HXsecondary amine R-X + :SH -  R-SH + :X - thiol R-X + :SR´  R-SR´ + :X - thioether Etc. Best when R-X is CH 3 or 1 o ! S N 2

2. dehydrohalogenation of alkyl halides | | | | — C — C — + KOH(alc.)  — C = C — + KX + H 2 O | | H X a)RX: 3 o > 2 o > 1 o b)no rearragement c)may yield mixtures  d)Saytzeff orientation e)element effect f)isotope effect g)rate = k [RX] [KOH] h)Mechanism = E2

CH 3 CHCH 3 + KOH(alc)  CH 3 CH=CH 2 Br isopropyl bromidepropylene CH 3 CH 2 CH 2 CH 2 -Br + KOH(alc)  CH 3 CH 2 CH=CH 2 n-butyl bromide 1-butene CH 3 CH 2 CHCH 3 + KOH(alc)  CH 3 CH 2 CH=CH 2 Br 1-butene 19% sec-butyl bromide + CH 3 CH=CHCH 3 2-butene 81%

3. preparation of Grignard reagent CH 3 CH 2 CH 2 -Br + Mg  CH 3 CH 2 CH 2 -MgBr n-propyl bromiden-propyl magnesium bromide 4.reduction CH 3 CH 2 CH 2 -Br + Mg  CH 3 CH 2 CH 2 -MgBr CH 3 CH 2 CH 2 -MgBr + H 2 O  CH 3 CH 2 CH 3 + Mg(OH)Br propane CH 3 CH 2 CHCH 3 + Sn/HCl  CH 3 CH 2 CH 2 CH 3 + SnCl 2 Cl sec-butyl chloriden-butane

Alcohols nomenclature syntheses 1. oxymercuration-demercuration 2. hydroboration-oxidation hydrolysis of some alkyl halides reactions 1. HX 2. PX 3 3. dehydration 4. as acids 5. ester formation 6. oxidation

Alcohols, nomenclature CH 3 CH 3 CH 3 CHCH 2 CHCH 3 CH 3 CCH 3 OH OH 4-methyl-2-pentanoltert-butyl alcohol 2-methyl-2-propanol 2 o 3 o CH 3 HO-CHCH 2 CH 3 CH 3 CH 2 CH 2 -OH sec-butyl alcoholn-propyl alcohol 2-butanol 1-propanol 2 o 1 o

Alcohols, syntheses 1. oxymercuration-demercuration: a)Markovnikov orientation. b)100% yields. c)no rearrangements CH 3 CH 2 CH=CH 2 + H 2 O, Hg(OAc) 2 ; then NaBH 4  CH 3 CH 2 CHCH 3 OH

2. hydroboration-oxidation: Anti-Markovnikov orientation.  100% yields. no rearrangements CH 3 CH 2 CH=CH 2 + (BH 3 ) 2 ; then H 2 O 2, NaOH  CH 3 CH 2 CH 2 CH 2 -OH

Reaction of alcohols 1. with HX: R-OH + HX  R-X + H 2 O a) HX: HI > HBr > HCl b) ROH: 3 o > 2 o > CH 3 > 1 o S N 1/S N 2 c) May be acid catalyzed d) Rearrangements are possible except with most 1 o alcohols.

CH 3 CH 2 CH 2 CH 2 -OH + NaBr, H 2 SO 4, heat  CH 3 CH 2 CH 2 CH 2 -Br n-butyl alcohol (HBr)n-butyl bromide 1-butanol1-bromobutane CH 3 CH 3 CH 3 CCH 3 + HCl  CH 3 CCH 3 OH Cl tert-butyl alcoholtert-butyl chloride 2-methyl-2-propanol2-chloro-2-methylpropane CH 3 -OH + HI, H +,heat  CH 3 -I methyl alcohol methyl iodide methanol iodomethane

2.With PX 3 ROH + PX 3  RX a)PX 3 = PCl 3, PBr 3, P + I 2 b)No rearrangements c)ROH: CH 3 > 1 o > 2 o CH 3 CH 3 CH 3 CCH 2 -OH + PBr 3  CH 3 CCH 2 -Br CH 3 CH 3 neopentyl alcohol 2,2-dimethyl-1-bromopropane

3.Dehydration of alcohols | | | | — C — C — acid, heat  — C = C — + H 2 O | | H OH a)ROH: 3 o > 2 o > 1 o b)acid is a catalyst c)rearrangements are possible  d)mixtures are possible  e)Saytzeff f)mechanism is E1

CH 3 CH 2 -OH + 95% H 2 SO 4, 170 o C  CH 2 =CH 2 CH 3 CH 3 CH 3 CCH % H 2 SO 4, o C  CH 3 C=CH 2 OH CH 3 CH 2 CHCH % H 2 SO 4, 100 o C  CH 3 CH=CHCH 3 OH + CH 3 CH 2 CH=CH 2 CH 3 CH 2 CH 2 CH 2 -OH + H +, 140 o C  CH 3 CH 2 CH=CH 2 rearrangement!  + CH 3 CH=CHCH 3

4)As acids. a)With active metals: ROH + Na  RONa + ½ H 2  CH 3 CH 2 -OH + K  CH 3 CH 2 -O - K + + H 2 b)With bases: CH 4 < NH 3 < ROH < H 2 O < HF ROH + NaOH  NR! CH 3 CH 2 OH + CH 3 MgBr  CH 4 + Mg(Oet)Br

5.Ester formation. CH 3 CH 2 -OH + CH 3 CO 2 H, H +  CH 3 CO 2 CH 2 CH 3 + H 2 O CH 3 CH 2 -OH + CH 3 COCl  CH 3 CO 2 CH 2 CH 3 + HCl CH 3 -OH + CH 3 SO 2 Cl  CH 3 SO 3 CH 3 + HCl Esters are alkyl “salts” of acids.

6.Oxidation Oxidizing agents: KMnO 4, K 2 Cr 2 O 7, CrO 3, NaOCl, etc. Primary alcohols: CH 3 CH 2 CH 2 -OH + KMnO 4, etc.  CH 3 CH 2 CO 2 H carboxylic acid Secondary alcohols: OH O CH 3 CH 2 CHCH 3 + K 2 Cr 2 O 7, etc.  CH 3 CH 2 CCH 3 ketone Teriary alcohols: no reaction.

Primary alcohols can also be oxidized to aldehydes: CH 3 CH 2 CH 2 -OH + C 5 H 5 NHCrO 3 Cl  CH 3 CH 2 CHO pyridinium chlorochromate aldehyde or CH 3 CH 2 CH 2 -OH + K 2 Cr 2 O 7, special conditions 

Ethers nomenclature syntheses 1. Williamson Synthesis 2. alkoxymercuration-demercuration reactions 1. acid cleavage

EthersR-O-R or R-O-R´ Nomenclature: simple ethers are named: “alkyl alkyl ether” “dialkyl ether” if symmetric CH 3 CH 3 CH 3 CH 2 -O-CH 2 CH 3 CH 3 CH-O-CHCH 3 diethyl ether diisopropyl ether

R-OH + Na  R-O - Na +  R-O-R´ R´-OH + HX  R´-X (CH 3 ) 2 CH-OH + Na  (CH 3 ) 2 CH-O - Na + +  CH 3 CH 2 CH 2 -O-CH(CH 3 ) 2 CH 3 CH 2 CH 2 -OH + HBr  CH 3 CH 2 CH 2 -Br isopropyl n-propyl ether note: the alkyl halide is primary! 1. Williamson Synthesis of Ethers

CH 3 CH 2 CH 2 -OH + Na  CH 3 CH 2 CH 2 -ONa +  CH 3 CH 2 CH 2 -O-CH(CH 3 ) 2 (CH 3 ) 2 CH-OH + HBr  (CH 3 ) 2 CH-Br 2 o The product of this attempted Williamson Synthesis using a secondary alkyl halide results not in the desired ether but in an alkene! The alkyl halide in a Williamson Synthesis must beCH 3 or 1 o ! 

2. alkoxymercuration-demercuration: a)Markovnikov orientation. b)100% yields. c)no rearrangements CH 3 CH=CH 2 + CH 3 CHCH 3, Hg(TFA) 2 ; then NaBH 4  OH CH 3 CH 3 CH 3 CH-O-CHCH 3 diisopropyl ether Avoids the elimination with 2 o /3 o RX in Williamson Synthesis.

Reactions, ethers: 1.Acid cleavage. R-O-R´ + (conc) HX, heat  R-X + R´-X CH 3 CH 2 -O-CH 2 CH 3 + HBr, heat  2 CH 3 CH 2 -Br

Alkenes nomenclature syntheses 1. dehydrohalogenation of an alkyl halide 2. dehydration of an alcohol 3. dehalogenation of a vicinal dihalide 4. reduction of an alkyne reactions 1. addition of hydrogen10. hydroboration-oxidation 2. addition of halogens11. addition of free radicals 3. addition of hydrogen halides12. polymerization 4. addition of sulfuric acid13. addition of carbenes 5. addition of water14. epoxidation 6. halohydrin formation15. hydroxylation 7. dimerization16. allylic halogenation 8. alkylation17. ozonolysis 9. oxymercuration-demercuration18. vigorous oxidation

Alkenes, nomenclature C 3 H 6 propylene CH 3 CH=CH 2 C 4 H 8 butylenesCH 3 CH 2 CH=CH 2 α-butylene 1-butene CH 3 CH 3 CH=CHCH 3 CH 3 C=CH 2 β-butylene isobutylene 2-butene2-methylpropene

* ** * (Z)-3-methyl-2-pentene ( 3-methyl-cis-2-pentene ) (E)-1-bromo-1-chloropropene

1. dehydrohalogenation of alkyl halides | | | | — C — C — + KOH(alc.)  — C = C — + KX + H 2 O | | H X a)RX: 3 o > 2 o > 1 o b)no rearragement c)may yield mixtures  d)Saytzeff orientation e)element effect f)isotope effect g)rate = k [RX] [KOH] h)Mechanism = E2

CH 3 CHCH 3 + KOH(alc)  CH 3 CH=CH 2 Br isopropyl bromidepropylene CH 3 CH 2 CH 2 CH 2 -Br + KOH(alc)  CH 3 CH 2 CH=CH 2 n-butyl bromide 1-butene CH 3 CH 2 CHCH 3 + KOH(alc)  CH 3 CH 2 CH=CH 2 Br 1-butene 19% sec-butyl bromide + CH 3 CH=CHCH 3 2-butene 81%

2.dehydration of alcohols: | | | | — C — C — acid, heat  — C = C — + H 2 O | | H OH a)ROH: 3 o > 2 o > 1 o b)acid is a catalyst c)rearrangements are possible  d)mixtures are possible  e)Saytzeff f)mechanism is E1

CH 3 CH 2 -OH + 95% H 2 SO 4, 170 o C  CH 2 =CH 2 CH 3 CH 3 CH 3 CCH % H 2 SO 4, o C  CH 3 C=CH 2 OH CH 3 CH 2 CHCH % H 2 SO 4, 100 o C  CH 3 CH=CHCH 3 OH + CH 3 CH 2 CH=CH 2 CH 3 CH 2 CH 2 CH 2 -OH + H +, 140 o C  CH 3 CH 2 CH=CH 2 rearrangement!  + CH 3 CH=CHCH 3

3.dehalogenation of vicinal dihalides | | | | — C — C — + Zn  — C = C — + ZnX 2 | | X X eg. CH 3 CH 2 CHCH 2 + Zn  CH 3 CH 2 CH=CH 2 + ZnBr 2 Br Br Not generally useful as vicinal dihalides are usually made from alkenes. May be used to “protect” a carbon-carbon double bond.

CH 3 H \ / Na or Li C = C anti- NH 3 (liq) / \ H CH 3 trans-2-butene CH 3 C  CCH 3 H H \ / H 2, Pd-C C = C syn- Lindlar catalyst / \ CH 3 CH 3 cis-2-butene 4. reduction of alkyne

Alkenes, reactions 1. Addition of hydrogen (reduction). | | | | — C = C — + H 2 + Ni, Pt, or Pd  — C — C — | | H H a) Requires catalyst. b)#1 synthesis of alkanes CH 3 CH=CHCH 3 + H 2, Ni  CH 3 CH 2 CH 2 CH 3 2-butene n-butane

2) Addition of halogens. | | | | — C = C — + X 2  — C — C — | | X X a)X 2 = Br 2 or Cl 2 b)test for unsaturation with Br 2 CH 3 CH 2 CH=CH 2 + Br 2 /CCl 4  CH 3 CH 2 CHCH 2 Br Br 1-butene 1,2-dibromobutane

3.Addition of hydrogen halides. | | | | — C = C — + HX  — C — C — | | H X a)HX = HI, HBr, HCl b)Markovnikov orientation CH 3 CH=CH 2 + HI  CH 3 CHCH 3 I CH 3 CH 3 CH 2 C=CH 2 + HBr  CH 3 CCH 3 Br

4.Addition of sulfuric acid. | | | | — C = C — + H 2 SO 4  — C — C — | | H OSO 3 H alkyl hydrogen sulfate Markovnikov orientation. CH 3 CH=CH 2 + H 2 SO 4  CH 3 CHCH 3 O O-S-O OH

5.Addition of water. | | | | — C = C — + H 2 O, H +  — C — C — | | H OH a) requires acid b)Markovnikov orientation c)low yield  CH 3 CH 2 CH=CH 2 + H 2 O, H +  CH 3 CH 2 CHCH 3 OH

6.Addition of halogens + water (halohydrin formation): | | | | — C = C — + X 2, H 2 O  — C — C — + HX | | OH X a)X 2 = Br 2, Cl 2 b)Br 2 = electrophile CH 3 CH=CH 2 + Br 2 (aq.)  CH 3 CHCH 2 + HBr OH Br

7.Dimerization: CH 3 CH 3 CH 3 CH 3 C=CH 2 + H 2 SO 4, 80 o C  CH 3 C-CH=CCH 3 CH 3 + CH 3 CH 3 CH 3 C-CH 2 C=CH 2 CH 3

8.Alkylation: CH 3 CH 3 CH 3 C=CH 2 + CH 3 CHCH 3 + HF, 0 o C  CH 3 CH 3 CH 3 C-CH 2 CHCH 3 CH 3 2,2,4-trimethylpentane ( “isooctane” )

9. oxymercuration-demercuration: a) Markovnikov orientation. b) 100% yields. c) no rearrangements CH 3 CH 2 CH=CH 2 + H 2 O, Hg(OAc) 2 ; then NaBH 4  CH 3 CH 2 CHCH 3 OH

With alcohol instead of water: alkoxymercuration-demercuration: | | | | — C =C — + ROH, Hg(TFA) 2  — C — C — | | OR HgTFA | | | | — C — C — + NaBH 4  — C — C — | | | | OR HgTFA OR H ether

10. hydroboration-oxidation: a)#2 synthesis of alcohols. b)Anti-Markovnikov orientation.  c)100% yields. d)no rearrangements CH 3 CH 2 CH=CH 2 + (BH 3 ) 2 ; then H 2 O 2, NaOH  CH 3 CH 2 CH 2 CH 2 -OH

11.Addition of free radicals. | | | | — C = C — + HBr, peroxides  — C — C — | | H X a)anti-Markovnikov orientation. b)free radical addition CH 3 CH=CH 2 + HBr, peroxides  CH 3 CH 2 CH 2 -Br

12.Polymerization. CH 2 =CH 2 + heat, pressure  -(CH 2 CH 2 )- n n = 10,000+ polyethylene CH 3 CH=CH 2 polymerization  -(CH 2 CH)- n CH 3 polypropylene CH 2 =CHCl poly…  -(CH 2 CH)- n Cl polyvinyl chloride (PVC)

13.Addition of carbenes. | | | | — C = C — + CH 2 CO or CH 2 N 2, hν  — C — C —  CH 2 CH 2 “carbene” adds across the double bond | | — C = C —  CH 2

14. Epoxidation. | | C 6 H 5 CO 3 H | | — C = C — + (peroxybenzoic acid)  — C— C — O epoxide Free radical addition of oxygen diradical. | | — C = C —  O

15. Hydroxylation. (mild oxidation) | | | | — C = C — + KMnO 4  — C — C — syn | | OH OH OH | | | | — C = C — + HCO 3 H  — C — C — anti peroxyformic acid | | OH glycol

cis-2-butene + KMnO 2  meso-2,3-dihydroxybutane mp 34 o CH 3 H OH CH 3 trans-2-butene + KMnO 4  (S,S) & (R,R)-2,3-dihydroxybutane mp 19 o CH 3 H OH + HO H HO H H OH CH 3 CH 3 stereoselective and stereospecific

16.Allylic halogenation. | | | | | | — C = C — C — + X 2, heat  — C = C — C — + HX | | H  allyl X CH 2 =CHCH 3 + Br 2, 350 o C  CH 2 =CHCH 2 Br + HBr a) X 2 = Cl 2 or Br 2 b) or N-bromosuccinimide (NBS)

17.Ozonolysis. | | | | — C = C — + O 3 ; then Zn, H 2 O  — C = O + O = C — used for identification of alkenes CH 3 CH 3 CH 2 CH=CCH 3 + O 3 ; then Zn, H 2 O  CH 3 CH 3 CH 2 CH=O + O=CCH 3

18.Vigorous oxidation. =CH 2 + KMnO 4, heat  CO 2 =CHR + KMnO 4, heat  RCOOH carboxylic acid =CR 2 + KMnO 4, heat  O=CR 2 ketone

CH 3 CH 2 CH 2 CH=CH 2 + KMnO 4, heat  CH 3 CH 2 CH 2 COOH + CO 2 CH 3 CH 3 CH 3 C=CHCH 3 + KMnO 4, heat  CH 3 C=O + HOOCCH 3

Dienes nomenclature syntheses same as alkenes reactions same as alkenes special: conjugated dienes 1. more stable 2. preferred products of eliminations 3. give 1,2- & 1,4- addition products

(cumulated dienes are not very stable and are rare) isolated dienes are as you would predict, undergo addition reactions with one or two moles…  conjugated dienes are unusual in that they: 1)are more stable than predicted 2)are the preferred products of eliminations 3)give 1,2- plus 1,4-addition products

nomenclature: CH 2 =CHCH=CH 2 CH 3 CH=CHCH 2 CH=CHCH 3 1,3-butadiene 2,5-heptadiene conjugated isolated 2-methyl-1,3-butadiene (isoprene) conjugated

isolated dienes: (as expected) 1,5-hexadiene CH 2 =CHCH 2 CH 2 CH=CH 2 + H 2, Ni  CH 3 CH 2 CH 2 CH 2 CH=CH 2 CH 2 =CHCH 2 CH 2 CH=CH H 2, Ni  CH 3 CH 2 CH 2 CH 2 CH 2 CH 3 CH 2 =CHCH 2 CH 2 CH=CH 2 + Br 2  CH 2 CHCH 2 CH 2 CH=CH 2 Br Br CH 2 =CHCH 2 CH 2 CH=CH 2 + HBr  CH 3 CHCH 2 CH 2 CH=CH 2 Br CH 2 =CHCH 2 CH 2 CH=CH HBr  CH 3 CHCH 2 CH 2 CHCH 3 Br Br

conjugated dienes yield 1,2- plus 1,4-addition: CH 2 =CHCH=CH 2 + H 2, Ni  CH 3 CH 2 CH=CH 2 + CH 3 CH=CHCH 3 CH 2 =CHCH=CH H 2, Ni  CH 3 CH 2 CH 2 CH 3 CH 2 =CHCH=CH 2 + Br 2  CH 2 CHCH=CH 2 + CH 2 CH=CHCH 2 Br Br Br Br CH 2 =CHCH=CH 2 + HBr  CH 3 CHCH=CH 2 + CH 3 CH=CHCH 2 Br Br peroxides CH 2 =CHCH=CH 2 + HBr  CH 2 CH=CHCH 3 + CH 2 CH 2 CH=CH 2 Br Br

Alkynes nomenclature syntheses 1. dehydrohalogenation of vicinal dihalides 2. coupling of metal acetylides with alkyl halides reactions 1. reduction 2. addition of halogens 3. addition of hydrogen halides 4. addition of water 5. as acids 6. with Ag + 7. oxidation

Alkynes, nomenclature HC  CH ethyne acetylene CH 3 CH 3 CH 2 C  CHHC  CCHCH 2 CH 3 1-butyne 3-methyl-1-pentyne ethylacetylenesec-butylacetylene

Synthesis, alkynes: 1.dehydrohalogenation of vicinal dihalides H H H | | | — C — C — + KOH  — C = C — + KX + H 2 O | | | X X X H | — C = C — + NaNH 2  — C  C — + NaX + NH 3 | X

2.coupling of metal acetylides with 1 o /CH 3 alkyl halides R-C  C - Na + + R´X  R-C  C-R´ + NaX a)S N 2 b)R´X must be 1 o or CH 3 X CH 3 C  C - Li + + CH 3 CH 2 -Br  CH 3 C  CCH 2 CH 3

HC  CH + 2 H 2, Pt  CH 3 CH 3 [ HC  CH + one mole H 2, Pt  CH 3 CH 3 + CH 2 =CH 2 + HC  CH ] H \ / Na or Li C = C anti- NH 3 (liq) / \ H — C  C — \ / H 2, Pd-C C = C syn- Lindlar catalyst / \ H H Alkyne, reactions 1. Addition of hydrogen (reduction)

CH 3 H \ / Na or Li C = C anti- NH 3 (liq) / \ H CH 3 trans-2-butene CH 3 C  CCH 3 H H \ / H 2, Pd-C C = C syn- Lindlar catalyst / \ CH 3 CH 3 cis-2-butene

2.Addition of X 2 X X X | | | — C  C— + X 2  — C = C — + X 2  — C — C — | | | X X X Br Br Br CH 3 C  CH + Br 2  CH 3 C=CH + Br 2  CH 3 -C-CH Br Br Br

3.Addition of hydrogen halides: H H X | | | — C  C— + HX  — C = C — + HX  — C — C — | | | X H X a)HX = HI, HBr, HCl b)Markovnikov orientation Cl CH 3 C  CH + HCl  CH 3 C=CH 2 + HCl  CH 3 CCH 3 Cl Cl

4.Addition of water. Hydration. O — C  C — + H 2 O, H +, HgO  — CH2 — C— H OH — C = C — “enol” keto-enol tautomerism Markovnikov orientation.

CH 3 CH 2 C  CH + H 2 O, H 2 SO 4, HgO  1-butyne O CH 3 CH 2 CCH 3 2-butanone

5.As acids. terminal alkynes only! a)with active metals CH 3 C  CH + Na  CH 3 C  C - Na + + ½ H 2  b)with bases CH 4 < NH 3 < HC  CH < ROH < H 2 O < HF CH 3 C  CH + CH 3 MgBr  CH 4 + CH 3 C  CMgBr SA SB WA WB

6.Ag + terminal alkynes only! CH 3 CH 2 C  CH + AgNO 3  CH 3 CH 2 C  C - Ag +  CH 3 C  CCH 3 + AgNO 3  NR (not terminal) formation of a precipitate is a test for terminal alkynes.

CH 3 CH 2 C  CCH 3 + KMnO 4  CH 3 C  CH + hot KMnO 4  CH 3 C  CCH 3 + O 3 ; then Zn, H 2 O  CH 3 CH 2 COOH + HOOCCH 3 CH 3 COOH + CO 2 2 CH 3 COOH 7. Oxidation

Alicyclics nomenclature syntheses like alkanes, alkenes, alcohols, etc. reactions as expected exceptions: cyclopropane/cyclobutane

methylcyclopentane 1,1-dimethylcyclobutane trans-1,2-dibromocyclohexane

cyclopentene 3-methylcyclohexene1,3-cyclobutadiene

Cycloalkanes, syntheses A. Modification of a cyclic compound: H 2, Ni Sn, HCl Mg; then H 2 O

Cycloalkanes, reactions: 1.halogenation 2. combustion 3. cracking 4. exceptions Cl 2, heat + HCl

exceptions: H 2, Ni, 80 o CH 3 CH 2 CH 3 Cl 2, FeCl 3 Cl-CH 2 CH 2 CH 2 -Cl H 2 O, H + CH 3 CH 2 CH 2 -OH conc. H 2 SO 4 CH 3 CH 2 CH 2 -OSO 3 H HI CH 3 CH 2 CH 2 -I

exceptions (cont.) +H 2, Ni, 200 o  CH 3 CH 2 CH 2 CH 3

KOH(alc) H +, Δ Zn cyclohexene Cycloalkenes, syntheses

Cycloalkenes, reactions: 1.addition of H hydroboration-oxid. 2.addition of X addition of free radicals 3.addition of HX12. polymerization 4.addition of H 2 SO addition of carbenes 5.addition of H 2 O,H epoxidation 6.addition of X 2 + H 2 O15. hydroxylation 7.dimerization16. allylic halogenation 8.alkylation17. ozonolysis 9.oxymerc-demerc.18. vigorous oxidation

H 2, Pt Br 2, CCl 4 HBr H 2 SO 4 H 2 O, H + Br 2 (aq.) dimerization trans-1,2-dibromocyclohexane Markovnikov

HF H 2 O,Hg(OAc) 2 NaBH 4 (BH 3 ) 2 H 2 O 2, NaOH HBr, perox. polymer. CH 2 CO,hv PBA Markovnikov anti-Markovnikov anti-Markovinikov

KMnO 4 HCO 3 H Br 2, heat O 3 Zn, H 2 O KMnO 4, heat O=CHCH 2 CH 2 CH 2 CH 2 CH=O HO 2 CCH 2 CH 2 CH 2 CH 2 CO 2 H cis-1,2-cylohexanediol trans-1,2-cyclohexanediol

Epoxides nomenclature syntheses 1. epoxidation of alkenes reactions 1. addition of acids 2. addition of bases

Epoxides, nomenclature ethylene oxide propylene oxide cyclopentene oxide (oxirane) (methyloxirane) C 6 H 5 CO 3 H Synthesis: β-butylene oxidecis-2-butene

epoxides, reactions: 1)acid catalyzed addition H 2 O, H + CH 3 CH 2 OH, H + HBr OH CH 2 OH OH CH 3 CH 2 -O-CH 2 CH 2 OH CH 2 Br

OH CH 2 OH CH 3 CH 2 -O-CH 2 CH 2 -OH H 2 N-CH 2 CH 2 -OH CH 3 CH 2 CH 2 CH 2 -OH 2. Base catalyzed addition

Mechanisms: Free radical substitution S N 2 S N 1 E2 E1 ionic electrophilic addition free radical electrophilic addition Memorize (all steps, curved arrow formalism, RDS) and know which reactions go by these mechanisms!

Free Radical Substitution Mechanism initiating step: 1)X—X  2 X propagating steps: 2) X + R—H  H—X + R 3)R + X—X  R—X + X 2), 3), 2), 3)… terminating steps: 4) 2 X  X—X 5) R + X  R—X 6) 2 R  R—R

Substitution, nucleophilic, bimolecular (S N 2) CH 3 > 1 o > 2 o > 3 o

Substitution, nucleophilic, unimolecular (S N 1) 3 o > 2 o > 1 o > CH 3 1) 2)

Mechanism = elimination, bimolecular E2 3 o > 2 o > 1 o

Elimination, unimolecular E1 3 o > 2 o > 1 o

Free radical electrophilic addition of HBr: Initiating steps: 1) peroxide  2 radical 2) radical + HBr  radical:H + Br (Br electrophile) Propagating steps: 3) Br + CH 3 CH=CH 2  CH 3 CHCH 2 -Br (2 o free radical) 4) CH 3 CHCH 2 -Br + HBr  CH 3 CH 2 CH 2 -Br + Br 3), 4), 3), 4)… Terminating steps: 5)Br + Br  Br 2 Etc.