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Which molecule is more stable, 1,3-pentadiene or 1,4-pentadiene? Why?
1,3-pentadiene since the double bonds are conjugated
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Why is an allylic radical more stable than a 1-propyl radical?
The double bond in the allyl radical helps stabilize through resonance
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What conditions are required to convert propene to 3-bromopropene?
Br2 and either light or heat (radical bromination)
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Why do 1,3-dienes need to be s-cis oriented for the Diels-Alder reaction to be successful?
The diene must present its frontier orbitals in the same direction so that they may overlap with the pi bond of the dienophile
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Why is s-cis to s-trans interconversion hindered in acyclic 1,3-dienes?
There is significant overlap between the C-2 and C-3 p orbitals so the C-2-C-3 bond has some pi character.
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Why do SN1 reactions of allylic halides occur faster than in simple alkyl systems?
The allyl carbocation is stabilized by resonance and is formed faster than a simple alkyl carbocation
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Which is typically more stable in a chemical reaction, the kinetic or thermodynamic product?
The thermodynamic product
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Is the Diels-Alder reaction typically a stepwise or a concerted process?
Concerted; all bonds form and break at the same time
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Which dienes are usually more stable, isolated or conjugated, and why?
Conjugated; extra overlap between the pi bonds
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Are the s-cis and s-trans forms of an acyclic 1,3-diene isomers or conformers?
Conformers; they are readily interconverted unlike isomers
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