2009 ADA Sample Test Orgo #74

[FROGGBUSTER]

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It seems that increasing the length of the alkyl chain between 2 adjacent double bonds increases thermodynamic stability, but can someone explain it further? Thanks.

 

[Dew517]

I think D is the answer because it is on the only molecule that has the double bonds conjugated. The double bonds are conjugated which cause a delocalization of electrons which cause the molecule to be more stable.

btw what happend to answer choice A?

 

[FROGGBUSTER]

I think D is the answer because it is on the only molecule that has the double bonds conjugated. The double bonds are conjugated which cause a delocalization of electrons which cause the molecule to be more stable.

btw what happend to answer choice A?

lol I'm not sure, the sample test is so full of errors that they give you an Errata sheet listing the mistakes, haha.

But I don't think E is conjugated, that middle carbon is sp3-hybridized.

 

[Bis-GMA111]

http://www.youtube.com/watch?v=YNVq_GDZ1Nw

 

[mh0000]

D is the answer. A and B are allenes, which are much more reactive. D is conjugated as someone above stated. E is not conjugated

 

[FROGGBUSTER]

Oops, I think I misread twice, lol.

Thanks guys.