Term
| Thermodynamically, additions to alkenes should proceed to products with _____ of energy |
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Definition
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Definition
| adding reagents to the same side of the double bond in an alkene |
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Definition
| adding reagents to opposite sides of the double bond in an alkene |
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Term
| When steric hindrance inhibits hydrogenation on one face of a double bond, addition will take place exclusively to the _____ face |
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Definition
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Term
| An electrophilic oxidizing agent is capable of introducing a single _____ atom to connect both carbons of a double bond |
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Definition
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Term
| The process of introducing a single oxygen atom to connect both carbons of a double bond produces oxacyclopropanes, which may be converted into vicinal _____ diols |
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Definition
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Term
| The attachment of oxygen atoms to _____ alkene carbon gives vicinal syn diols by partial double-bond cleavage |
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Definition
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Term
| The attachment of oxygen atoms to each alkene carbon gives vicinal _____ diols by partial double-bond cleavage |
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Definition
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Term
| The OH group in peroxycarboxylic acids contains an _____ oxygen |
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Definition
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Term
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Definition
| the transformation of an alkene to an oxacyclopropane |
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Term
| "Epoxidation" is derived from "_____", one of the older common names for oxacyclopropanes |
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Definition
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Term
| Are additions in peroxide conditions faster or slower than ionic additions? |
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Definition
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Term
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Definition
| additions of radicals to an alkene in the presence of peroxides |
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Term
| What are the 2 initiation steps for the anti-Markovnikov hydrobromination in the presence of radicals? |
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Definition
1. the hemolytic cleavage of the weak RO-OR bond
2. reaction of the resulting alkoxy radical with hydrogen bromide |
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Term
| In anti-Markovnikov addition, the halogen atom's attack is _____, creating the relatively more stable secondary radical rather than the primary one |
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Definition
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Term
| In the radical mechanism, a _____ atom is the attacking species, creating the more stable radical center |
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Definition
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Term
| In the _____ mechanism, a halogen atom is the attacking species, creating the more stable radical center |
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Definition
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Term
| Which 2 H-X molecules do not give anti-Markovnikov addition products with alkenes? |
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Definition
| hydrogen chloride & hydrogen iodide |
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Term
| Can HCl & HI give anti-Markovnikov addition products with alkenes? |
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Definition
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Term
| What is the only H-X molecule that adds to an alkene under radical conditions to give anti-Markovnikov products? |
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Definition
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Term
| In bromination, only _____ addition is observed |
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Definition
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Term
| When the pi electron could of the alkene attacks one end of the Br2 molecule, what is formed? |
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Definition
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Term
| The halogenation of alkenes should not be confused with the halogenation of _____ |
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Definition
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Term
| _____ halogenation is a radical process that requires an initiation step to generate halogen atoms |
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Definition
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Term
| The nucleophile attacks the _____ carbon of the ring, because this carbon is more positively polarized than the other |
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Definition
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Term
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Definition
| oxidatively cleaving alkenes (pi and sigma bonds) through the reaction with ozone (O3) |
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Term
| Ozone is produced in the laboratory in an instrument called an _____, in which an arc discharge generates 3-4% ozone in a dry oxygen stream |
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Definition
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Definition
| the first isolable intermediate in ozonolysis; reduced directly in a subsequent step by exposure to zinc in acetic acid or by reaction with dimethyl sulfide |
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Term
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Definition
| the product of the initial electrophilic addition of ozone to the double bond of an alkene |
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Term
| 2 step mechanism of ozonolysis |
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Definition
1. molozonide formation & cleavage
2. ozonide formation & reduction |
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Term
| Transformations that end in hydrogenation are collectively called _____ |
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Definition
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Term
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Definition
| when a good nucleophile is present & a carbocation is intercepted after hydrogenation |
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Term
| In electrophilic addition, when the two vinyl carbons have the same substituents, protonation to either carbon furnishes the _____ intermediate cation |
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Definition
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Term
| If the carbon atoms participating in the double bond are not equally substituted, the proton from the hydrogen halide attaches itself to which carbon? |
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Definition
| the less substituted carbon |
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Term
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Definition
| protonation of an alkene results in the hydrogen bonding to the less substituted carbon |
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Term
| Why is Markovnikov rule true? |
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Definition
| the relative stability of the resulting carbocation intermediate |
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Term
| Which carbocations are the most stable? |
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Definition
| tertiary > secondary > primary |
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Term
| H-X adds to unsymmetric alkenes in such a way that the initial protonation gives ______ |
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Definition
| the more stable carbocation |
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Term
| Upon exposure of an alkene to an _____ solution of sulfuric acid, water acts as the nucleophile to trap the carbocation formed by initial protonation |
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Definition
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Term
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Definition
| when the elements of water add to the double bond |
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Term
| Are the steps reversible in the mechanism of alkene hydration? |
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Definition
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Term
| Treating the alcohol with _____ favors dehydration into the alkene, especially at elevated temperatures |
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Definition
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Term
| Is the E1 process that forms alkenes reversible? |
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Definition
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Term
| The INITIAL E1 formation of alkenes is under _____ control |
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Definition
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Term
| The net effect of E1 formation of alkenes is interconversion of the isomers to an equilibrium mixture, in which the _____ most stable isomer is the major component |
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Definition
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Term
| The E1 formation of alkenes is overall under _____ control |
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Definition
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Term
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Definition
| an electrophilic addition of a mercuric salt to an alkene; resulting compound is an alkyl-mercury derivative, from which the mercury can be removed in a subsequent step |
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Term
| oxymercuration-demercuration |
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Definition
| a mercuric acetate acts as the reagent; treatment of an alkene with this species in the presence of water leads to the corresponding addition product; then, the mercury-containing substituent is replaced by hydrogen through treatment with sodium borohydride in base; net result is hydration of the double bond to give an alcohol |
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Term
| What is the significance behind no carbocation being involved in oxymercuration-demercuration? |
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Definition
| oxymercuration-demercuration is not susceptible to the rearrangements that commonly occur under acidic condition |
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Term
| 4 step mechanism of oxymercuration-demercuration |
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Definition
1. dissociation
2. electrophilic attack
3. nucleophilic opening
4. reduction |
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Term
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Definition
| borane adding to double bonds without catalytic activation; discovered by H.C. Brown |
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Term
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Definition
| the addition of the elements of water to a double bond with opposite regioselectivity from Markovnikov (the OH group ends up at the less substituted carbon) |
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Term
| In hydroboration-oxidation, the OH group ends up at the _____ substituted carbon, an example of anti-Markovnikov addition |
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Definition
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Term
| In hydroboration, the addition occurs without the participation of carbocations; therefore, _____ are not observed |
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Definition
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