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Topic: Transesterification  (Read 2988 times)

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Offline IoanaD

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Transesterification
« on: November 15, 2009, 03:43:21 AM »
I know that transesterification of isopentenyl acetate to isoamyl acetate can be done with an acid and another alcohol that replaces the first R group. However, i am asked what other way we can perform the same transformation. Is there a way of reducing that double bond without touching the carbonyl? I was even thinking of protecting it via a bifunctional alcohol and then adding H2/Pd in order to selectively reduce the double bond.
Is there any other way of achieving this?

Offline Enantiomer

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Re: Transesterification
« Reply #1 on: November 15, 2009, 04:52:05 AM »
you're right on the money, you can protect the ketone via acetal formation and then add a selective catalst (I think LiAlH4, I think H2 Pd would accomplish this, as would LiAlH4 (I'm not 100% about this one, and since it is very difficult to handle in the lab H2 Pd would be the better choice either way)
http://en.wikipedia.org/wiki/Protecting_group

Offline Arctic-Nation

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Re: Transesterification
« Reply #2 on: November 15, 2009, 12:15:08 PM »
No. This is an ester we're talking about, not a ketone, so protecting groups are out. The easiest way to reduce double bonds is some noble metal/hydrogen combination. Most of those won't touch the ester functionality, unlike hydride reagents.

Offline movies

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Re: Transesterification
« Reply #3 on: November 21, 2009, 05:13:15 PM »
Also, LiAlH4 will not reduce isolate C–C double bonds (it would reduce the ester, however).  H2 + Pd/C is the way to go for this one.

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