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Organic Chemistry Questions: Nucleophile and Electrophile

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Please help me with the attached chemistry questions.

** Please see the attached file for the complete problem description **

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The majority of these problems involve carbonyl compounds reacting in the presence of the strong bases (alkali metal hydroxides and alkoxides). There are several types of reactivity you need to take into consideration when answering these questions.

First, the base must do something in the first step. In these cases, this something is deprotonation of what is called an enolizable hydrogen atom - a hydrogen on the carbon alpha to a carbonyl (aldehyde, ketone, ester, amide) or another similar electron withdrawing group (ie nitrile in the set given).
(please see the attached file)

In every case, this metal (sodium or potassium) enolate will be your nucleophile.
This nucleophile will seek out an electrophile. The electrophile will be another carbonyl (typically an aldehyde) which will react with what is called 1,2 addition or an unsaturated carbonyl through 1,4 addition. Further reactions such as another addition or dehydration will occur if possible.
(please see the attached file)

As you can see above, enolates perform 1,4 (called conjugate) addition when possible. This is rationalized because enolates are what are called soft nucleophiles and react at the soft electrophilic site of the unsaturated carbonyl. Another soft nucleophile is cuprates (R2CuLi). The hard electrophilic site in the unsaturated carbonyl is the carbonyl carbon itself (1,2 addition). An example of hard nucleophiles that react at this hard electrophilic site are Grignard reagents (RMgX)
(X = halogen).

1. First reaction: You first need a source of (please see the attached file). This is prepared from acetyl chloride and AlCl_3. (AcCl, AlCl_3) Benzene is the nucleophile, the acylium ion drawn above is the ...

Solution Summary

This solution explains how to solve a series of chemistry questions and provides illustrations of the reactions.

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