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what forms a cis alkene from an alkane?
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what makes an C=O go to an C-OH?
LAH- Lithium Aluminum Hydride
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If HBr is present with Hv or heat or ROOR then is it markovnikov or anti-markovnikov?
anti-markovnikov
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Initiation?
Br-Br split by homolysis into 2 free radicals
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Propagation?
- 3 arrows
- Br free radical and H will form a bond and leave the major compound forming HBr and a radical on the major compound
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Termination?
any 2 radicals forming a bond will terminate the reaction
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mCPBA (meta-chloroperoxy benzoic acid)
 - can substitute benzene w/ chlorine for "R"
- forms epoxides from alkenes
- 5 arrow mechanism
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mCPBA and Cyclohexane w/ Alkene Mechanism (cycloalkene)
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Dihydroxylation: clyclohexane w/alkene reacts with what to make cyclohexane with two -OH substituents (each on a C of alkene)? (2 possibilities)
- KMnO4, H2O, KOH
- 1.) OsO4 2.) NaHSO3, H2O
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Oxidative Cleavage: (alkene to ketone)
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Oxidative Cleavage: alkyne to carboxylic acid
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2° Alcohol to Ketone
- Harsher Oxidant: K2CrO7, H2O, H2SO4
- PCC (pyridinium chlorochromate)
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Alcohols reacting with PCC makes:
aldehydes
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Alcohols reacting with Harsher Oxidant: K2CrO7, H2O, H2SO4 makes:
carboxylic acid
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3 Rules for Resonance Stability
- 1.) Res. structure with more bonds and fewer charges is better
- 2.) Res. structure with every atom having octet is better
- 3.) Res. structure with the neg. charge on more electronegative atom is better
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Electrophile Addition 1,2 vs. 1,4
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Diels-Alder Reaction
- awarded Nobel Prize in 1950
- 3 arrows
- cis comformation diene reacts with alkene (dienophile) and using heat creates 2 new C-C bonds (cyclohexane)
- stereochemistry of dienophile retained in product
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Benzene and Br2 will or will not react?
will not react
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Criteria for Aromaticity (Huckel's Rule)
- 1.)Cyclic: no open chains
- 2.) Planar: on exam everything should be planar
- 3.) Complete Conjugation: p-orbitals on every atom in ring (pi bond attached to every atom)
- 4.) # of e-: 4n+2=#pi e- (n is whole number: 0,1,2,3)
- If 1-4 pass then it is aromatic
- If 1-4 pass with #4 as 4n= #pi e- (n is whole number: 0,1,2,3) then it is anti-aromatic
- neither is when one or more do not pass
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Aromaticity Stability: (least to most stable)
anti-aromatic < neither < aromatic
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Requirements for SN1
- Alkyle halide: tertiary > secondary > primary
- weak generally neutral nucleophile
- polar protic solvent (water, alcohols, and carboxylic acids)
- sterechemistry: mix of retention and inversion
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Requirements for SN2
- Alkyle halide: primary > secondary > tertiary
- strong generally negative nucleophile
- polar aprotic solvent (acetone, DMSO, acetonitrile, or DMF)
- stereochemistry: inversion
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Requirements for E1
- Reactivity: primary < secondary < tertiary
- Base: weak base, good nucleophile (+ SN1 product: backside attack)
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Requirements for E2
- strong base, but weak nucleophile
- better leaving group
- polar aprotic solvent
- R-X Substrate (primary < secondary < tertiary)
- Hydrogen atom and halide atom must be in anti-periplanar position
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Primary Halides Reactivity
- E1/SN1-not possible
- SN2-good nucleophile
- E2- strong/hindered base
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Secondary Halides Reactivity
- Strong Nucleophile ---> SN2
- Strong not hindered base ---> SN2 + E2
- Strong bulky base ---> E2
- Weak Base and nucleophile ---> SN1/E1
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Tertiary Halides Reactivity
- SN2 ---> not possible
- Strong base ---> E2
- Weak base/nucleophile ---> E1/SN1
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Primary Alcohols
- Strong, weak nucleophilic acid ---> E2
- strong nucleophile and acid (HBr, HI) ---> SN2 (racemic mixture)
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Reducing Agents
- 1. H2 (acid catalyzed)
- 2. Na + NH3
- 3. LiAlH4 or NaBH4
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Reduction of Alkenes
- 1. Use H2 with palladium/carbon catalyst
- 2. Syn addition of hydrogen atoms
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