Ochem ch 7 structure and synthesis of alkenes part 2 (pi bond, elements of unsaturation, heteroat
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in terms of cis-trans isomerism, cycloalkenes are assumed to be ____
____ cycloalkenes are not stable unless the ring has at least 8 carbons
Is it possible for cyclooctene molecule to have trans isomerism?
Explain E-Z nomenclature
if high priority groups are on the same side, the name is Z and if high priority groups are on opposite sides, the name is E
why are more substituted alkenes more stable?
more substituted alkenes are less sterically hindered
Order the following in terms of their stability
geminal, trans, cis
cis < geminal < trans
Are small cycloalkenes stable?
why are small cycloalkenes not stable?
small cycloalkenes have addition ring strain
For cyclodecene and larger cycloalkenes, the ___ double bond is almost as stable as the ___
What are the physical properties of alkenes
they have pretty much the same physical properties as alkanes. They have low boiling points (which the boiling points increasing with mass). Branched alkenes have lower boiling points. They are less dense than water. They are also slightly polar (but not solbule inwateR)
Explain how alkenes are slightly polar
alkene pi bond is polarizable, so instantaneous dipole-dipole interactions occur. Also alkyl groups are electron-donating toward the pi bond, so may have a small dipole moment
what are the four reactions by which alkenes are produced?
E2 reaction, E1 reaction, Dehalogenation of vicinal dibromides, dehydration of alcohols