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Definition
| C's adjacent to a phenyl group |
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| C's adjacent to an alkene |
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| reactivity of benzylic and allylic C's |
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Definition
| tend to be more reactive than non-benzyllic and non-allylic |
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| the product in a reaction that forms faster |
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| more stable product of a chemical rxn (more stable can be due to less crowded) |
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| depiction of the Diels-Alder mechanism |
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| alkene that seeks out diene |
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| examples of a rxn using the Diels-Alder process |
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| the most common method of preparing conjugated dienes |
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Definition
| based-induces addition of allylic halides |
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| what's more stable: conjugated diene or nonconjugated diene? |
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Definition
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| how we know conjugated dienes are more stable than nonconjugated dienes |
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Definition
| lower heat of hydrogenation, which means they release less heat on hydrogenation |
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| the stability of 1,3-butadiene may be due to... |
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Definition
| the greater amount of s character of the C-C single bond between the 2bl bonds |
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Term
| how molecular orbital theory offers an explanation for the stability of 1,3-butadiene |
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Definition
-if we combine 4 adjacent p orbitals, we generate a set of 4 molecular orbitals
-bonding electrons go into the lower molecular orbitals
-the lowest molecular orbital has a bonding interaction between C2 and C3 that gives that bond partial 2bl-bond character
-the pi electrons of butadiene are delocalized over this entire pi framework |
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Term
| if we combine 4 adjacent p orbitals, we generate... |
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Definition
| a set of 4 molecular orbitals |
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Term
| the molecular orbitals bonding electrons go into |
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Definition
| the lower molecular orbitals |
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Term
| how the C2-C3 bond in 1,3-butadiene obtains partial 2bl bond character |
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Definition
| the lowest MO has a bonding interaction between C2 and C3 that gives that bond partial 2bl-bond character |
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Term
| types of reactions of conjugated dienes |
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Definition
-electrophilic addition to conjugated dienes
-the Diels-Alder cycloaddition reaction
-diene polymers |
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Term
| the products yielded in rxns of conjugated dienes in electrophilic addition rxns |
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Definition
both...
-1,2 addition
-1,4 addition |
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Term
| in electrophilic addition of conjugated dienes, addition of ______ gives an allylic carbocation intermediate that is resonance-stabilized |
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Definition
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Term
| in electrophilic addition of conjugated dienes, addition of an electrophile gives ______ carbocation intermediate that is resonance-stabilized |
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Definition
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| in electrophilic addition of conjugated dienes, addition of an electrophile gives an allylic ______ that is resonance-stabilized |
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Definition
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| in electrophilic addition of conjugated dienes, addition of an electrophile gives an allylic carbocation intermediate that is ______ |
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Definition
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| in electrophilic addition of conjugated dienes, addition of the ______ in the 2nd step of the rxn can occur at either end of the carbocation to yield 2 products |
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Definition
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| in electrophilic addition of conjugated dienes, addition of the nucleophile in the ______ step of the rxn can occur at either end of the carbocation to yield 2 products |
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Definition
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| in electrophilic addition of conjugated dienes, addition of the nucleophile in the 2nd step of the rxn can occur at ______ end of the carbocation to yield 2 products |
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Definition
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Term
| in electrophilic addition of conjugated dienes, addition of the nucleophile in the 2nd step of the rxn can occur at either end of the ______ to yield 2 products |
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Definition
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Term
| in electrophilic addition of conjugated dienes, addition of the nucleophile in the 2nd step of the rxn can occur at either end of the carbocation to yield ______ |
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Definition
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| ______ react in electrophilic addition reactions to give products of both 1,2-addition and 1,4 addition |
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Definition
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| conjugated dienes react in ______ reactions to give products of both 1,2-addition and 1,4 addition |
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Definition
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Term
| conjugated dienes react in electrophilic addition reactions to give products of ______ |
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Definition
| both 1,2-addition and 1,4 addition |
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| the ratio of products in ______ of conjugated dienes can vary if the reaction is carried out under conditions of kinetic control or thermodynamic control |
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Definition
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| the ratio of products in electrophilic addition of ______ can vary if the reaction is carried out under conditions of kinetic control or thermodynamic control |
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| the ratio of products in electrophilic addition of conjugated dienes can vary if the reaction is carried out under conditions of ______ control or ______ control |
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Definition
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| under conditions of ______ (lower temp), the product whose formation has the lower energy of activation forms in grater amounts |
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Definition
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| under conditions of kinetic control (______), the product whose formation has the lower energy of activation forms in grater amounts |
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Definition
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| under conditions of kinetic control (lower temp), the product whose formation has the ______ forms in grater amounts |
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Definition
| lower energy of activation |
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| under conditions of ______ (high temperature), the more stable product (the product whose formation has a larger negative value of ΔG°) forms in greater amounts |
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Definition
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| under conditions of thermodyynamic control (______), the more stable product (the product whose formation has a larger negative value of ΔG°) forms in greater amounts |
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Definition
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| under conditions of thermodyynamic control (high temperature), the ______ product (the product whose formation has a larger negative value of ΔG°) forms in greater amounts |
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Definition
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| under conditions of thermodyynamic control (high temperature), the more stable product (______) forms in greater amounts |
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Definition
| the product whose formation has a larger negative value of ΔG° |
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Term
| in electrophilic addition rxns of conjugated dienes, which product preferentially forms at low temp? |
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Definition
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| in electrophilic addition rxns of conjugated dienes, which product preferentially forms at low high? |
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Definition
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| in electrophilic addition rxns of conjugated dienes, is the 1,2 adduct kinetic or thermodynamic? |
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Definition
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| in electrophilic addition rxns of conjugated dienes, is the 1,4 adduct kinetic or thermodynamic? |
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Definition
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| how the Diels-Alder cycloaddition rxn occurs |
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Definition
| -a diene can react with certain alkenes to form a cyclic product
-this rxn forms 2 new C-C bonds in a single step
-the rxn occurs by a pericyclic mechanism, which takes place in a step by a cyclic redistribution of electrons
-in the rxn, sigma overlap occurs between the 2 alkene p orbitals and the 2 p orbitals on C's 1 and 4 of the diene
-the 2 alkene C's and C1 and C4 of the diene rehybridize from sp2 to sp3, and C2 and C3 of the diene remain sp2 hybridized |
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| in the Diels-Alder cycloaddition rxn, ______ can react with certain alkenes to form a cyclic product |
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Definition
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| in the Diels-Alder cycloaddition rxn, a diene can react with ______ to form a cyclic product |
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Definition
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| in the Diels-Alder cycloaddition rxn, a diene can react with certain alkenes to form ______ |
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Definition
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| the Diels-Alder rxn forms ______ in a single step |
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Definition
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| the Diels-Alder rxn occurs by ______, which takes place in a step by a cyclic redistribution of electrons |
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Definition
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| the Diels-Alder rxn occurs by a pericyclic mechanism, which takes place in a... |
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Definition
| step by a cyclic redistribution of electrons |
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Term
| the Diels-Alder rxn occurs by a pericyclic mechanism, which takes place in a step by a ______ of electrons |
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Definition
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| the Diels-Alder rxn occurs by a pericyclic mechanism, which takes place in a step by a cyclic redistribution of ______ |
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Definition
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| in the Diels-Alder rxn, ______ occurs between the 2 alkene p orbitals and the 2 p orbitals on C's 1 and 4 of the diene |
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Definition
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Term
| in the Diels-Alder rxn, sigma overlap occurs between the ______ and the 2 p orbitals on C's 1 and 4 of the diene |
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Definition
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Term
| in the Diels-Alder rxn, sigma overlap occurs between the 2 alkene p orbitals and the ______ on C's 1 and 4 of the diene |
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Definition
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Term
| in the Diels-Alder rxn, sigma overlap occurs between the 2 alkene p orbitals and the 2 p orbitals on ______ |
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Definition
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Term
| in the Diels-Alder rxn, the ______ rehybridize from sp2 to sp3, and C2 and C3 of the diene remain sp2 hybridized |
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Definition
| 2 alkene C's and C1 and C4 of the diene |
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Term
| in the Diels-Alder rxn, the 2 alkene C's and C1 and C4 of the diene rehybridize from ______ to ______, and C2 and C3 of the diene remain sp2 hybridized |
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Definition
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Term
| in the Diels-Alder rxn, the 2 alkene C's and C1 and C4 of the diene rehybridize from sp2 to sp3, and ______ remain sp2 hybridized |
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Definition
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Term
| in the Diels-Alder rxn, the 2 alkene C's and C1 and C4 of the diene rehybridize from sp2 to sp3, and C2 and C3 of the diene remain ______ |
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Definition
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| in the Diels-Alder rxn, the ______ must have an electron-withdrawing group and may contain a triple bond |
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Definition
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| in the Diels-Alder rxn, the dienophile must have ______ and may contain a triple bond |
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Definition
| an electron-withdrawing group |
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| in the Diels-Alder rxn, the dienophile must have an electron-withdrawing group and may contain ______ |
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Definition
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| in the Diels=Alder rxn, the ______ of the dienophile is maintained during the reaxtion |
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Definition
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| in the Diels=Alder rxn, the stereochemistry of the ______ is maintained during the reaxtion |
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Definition
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Term
| why only endo product is formed during the Diels-Alder rxn |
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Definition
| because orbital overlap is greater in the transition state than for exo product |
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Term
| ______ in a bicyclic ring system is endo if it is syn to the larger of the other 2 bridges |
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Definition
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| a substituent in ______ is endo if it is syn to the larger of the other 2 bridges |
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Definition
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Term
| a substituent in a bicyclic ring system is ______ if it is syn to the larger of the other 2 bridges |
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Definition
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Term
| a substituent in a bicyclic ring system is endo if... |
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Definition
| it is syn to the larger of the other 2 bridges |
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Term
| what a diene must do to undergo the Diels-Alder rxn |
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Definition
| it must adopt an s-cis ("cis-like") conformation in order to undergo the Diels-Alder rxn |
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Term
| the dienes that can undergo the Diels-Alder rxn |
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Definition
| the dienes that can rotate to achieve an s-cis conformation |
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| the dienes that can't undergo the Diels-Alder rxn |
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Definition
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| reactivity of dienes with fixed s-cis geometry |
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Definition
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| why cis-trans isomerism is possible in dienes |
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Definition
| because 2bl bonds remain in the polymer |
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Term
| polymerization of dienes can be initiated by... |
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Definition
| either a radical or an acid |
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Term
| polymerization of dienes occurs by... |
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Definition
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Term
| how vulcanization hardens rubber |
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Definition
| heating it with S forms cross links that lock the chains together |
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| rubber's ability to stretch and contract is due to... |
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Definition
| the irregular shapes of the polymer chains |
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| kinetic conditions for a rxn |
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Definition
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| thermodynamic conditions for a rxn |
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Definition
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| which product is more stable? kinetic or thermodynamic? |
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Definition
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| when the kinetic product wins |
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Definition
| when you don't let equilibrium be established |
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