23-5. Mixed Aldol Reactions

　今回は 23-5. 混合アルドール反応 を要約します。

 This theme is 23-5. Mixed Aldol Reactions.

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23-5. Mixed Aldol Reactions

 An aldol reaction occurs with not only two same carbonyl partners, but also two different ones.  When we use different aldehyde or ketone partners in the reaction, four possible products are yielded as below.  Such the reaction isn't pragmatic.

 However, in the case of two reaction conditions shown as below, a single product is given from a mixed aldol reaction.

Condition (1)
 : One of carbonyl partners has no α hydorgens, but has an unhindered carbonyl group (such as formaldehyde or denzaldehyde).
→ It can't be converted into an enolate ion (donor).  
     It's a good accepter or nucleophiles.

ex)

Condition (2)
 : One of carbonyl partners is much more acidic than the other.
→ It's converted into an enolate ion preferentially.

ex)

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　以上、23-5. 混合アルドール反応でした。
　次回は 23-6. 分子内アルドール反応を要約します。

 23-5. Mixed Aldol Reactions has finished.
 I'm going to summarize 23-6. Intramolecular Aldol Reaction for next entry.