5
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I'd expect an extended enolate to be more stable than a normal enolate, when both can form, but my textbook suggests otherwise.

What is the stability of an extended enolate compared with a normal enolate? For example, following an enolate alkylation of the molecule depicted below, which product ($\alpha$- or $\gamma$-alkylated) will form?

enter image description here

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    $\begingroup$ It might be beneficial if you could provide a reference to your textbook. $\endgroup$ – andselisk Dec 15 '17 at 19:12
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    $\begingroup$ It probably depends on the deprotonation conditions $\endgroup$ – orthocresol Dec 15 '17 at 22:16
  • $\begingroup$ @orthocresol Thanks! But could you please elaborate? Do you mean bulkiness of the base? How could you favour one product over the other? $\endgroup$ – GingerBadger Dec 15 '17 at 22:18
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    $\begingroup$ I was looking for a post, because it has been discussed here before, and I found it: chemistry.stackexchange.com/a/43024/16683 $\endgroup$ – orthocresol Dec 15 '17 at 22:20
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    $\begingroup$ With LDA for example you can form a six-membered TS (Ireland model) with a $\ce{C=O...Li}$ interaction. I've heard that the model is a simplification of the truth, but the bottom line is that there's probably some kind of involvement of the carbonyl group. $\endgroup$ – orthocresol Dec 15 '17 at 22:25

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