{"id":826,"date":"2026-09-15T04:18:22","date_gmt":"2026-09-15T04:18:22","guid":{"rendered":"http:\/\/box5250.temp.domains\/~aceorgan\/blog\/?p=826"},"modified":"2026-09-15T04:18:22","modified_gmt":"2026-09-15T04:18:22","slug":"nucleophilic-attack-on-a-carbonyl-with-study-guide","status":"publish","type":"post","link":"https:\/\/www.aceorganicchem.com\/blog\/nucleophilic-attack-on-a-carbonyl-with-study-guide\/","title":{"rendered":"Nucleophilic attack on a carbonyl [with study guide]"},"content":{"rendered":"\n

Nucleophilic attack on a carbonyl is one of the most important reactions in organic chemistry. Not only is it a good way to turn a carbonyl into an alcohol, it becomes the gateway for that alcohol to interconvert into many other functional groups. That’s why nucleophilic attack on a ketone or aldehyde is very important for you to understand. But let’s move on first. Here are a couple of examples of nucleophilic attack on a carbonyl:<\/p>\n\n\n\n

\"carbonyls\"<\/a><\/figure><\/div>\n\n\n\n

The mechanism is also important understand. It all starts with the nucleophile attacking the carbonyl at the carbon.  Attack occurs at this position because there is a partial positive charge on the carbonyl carbon, meaning it is electrophilic.  (You can also confirm this by drawing the resonance structure) This forms a tetrahedral intermediate, with a negative charge on the oxygen.<\/p>\n\n\n\n

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At this point the pi bond has been broken and the intermediate alkoxide is formed. If the carbonyl that was attacked is a ketone or aldehyde, the negative oxygen or alkoxide will pick up a proton during work up and become the alcohol. If an ester or acid halide was attacked, the carbonyl is reformed but we will look at that reaction later.<\/p>\n\n\n\n

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Remember when doing these type of reactions, there are more than one type of nucleophile that can attack the carbonyl. Lewis acids can also be used as catalysts in this type of reaction to accelerate the formation of product. The Lewis acid acts to draw electron density away from the oxygen which in turn pulls electron density out of the pi bond. This causes the carbon of the carbonyl to become much more electrophilic and therefore much more reactive. <\/p>\n\n\n\n

Some common nucleophiles you will see attack a carbonyl are listed below:<\/p>\n\n\n\n

  1. Grignard reagents, such as CH3MgBr, CH3CH2MgCl<\/li>
  2. Organolithiums, such as CH3Li, CH3CH2Li<\/li>
  3. Alkoxides, such as NaOCH3, and NaOCH2CH3<\/li>
  4. Cyano groups, such as NaCN<\/li><\/ol>\n