I am reading a book which is saying about the Syn-Anti nomenclature of oximes. It is showing this molecule to be Syn-methyl-ethyl ketoxime.

Syn-methyl-ethyl ketoxime

I can't understand what is a ketoxime and how is there nomenclature done. Can somebody explain please ?


2 Answers 2


An oxime is a chemical compound belonging to the imines, with the general formula $\ce{(R^1)(R^2)C=N-O H}$,

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How is the nomenclature of methyl-ethyl ketoxime done?

The answer is :
Look at your photo.
1. On the left side you can see "$\ce{CH3-CH2 -}$" (ethyl).
2. On the right side you can see "$\ce{CH3 -}$" (methyl).
3. On the middle you can see "$\ce{C=N-O-H}$" (ketoxime).
Now assemble (1 & 2 & 3 ) ..then you will have the name "methyl-ethyl ketoxime".

For more you can see : https://en.wikipedia.org/wiki/Oxime


According to the old IUPAC recommendations (1979 as well as 1993), compounds having the general structure $\ce{R-CH=N-OH}$ or $\ce{RR'C=N-OH}$ are called generically ‘oximes’. They are further classified as ‘aldoximes’ and ‘ketoximes’, respectively. They are named by placing the functional class name ‘oxime’ as a separate word after the name of the corresponding aldehyde $\ce{R-CH=O}$ or ketone $\ce{RR'C=O}$, respectively.
Therefore, the systematic name of your example according to the principles of functional class nomenclature is butan-2-one oxime.

According to the current version of Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book), functional modifiers are still acceptable for general nomenclature purposes, but the preferred IUPAC names (PIN) are substitutive names for oximes. They are named substitutively as ‘ylidene’ derivatives of hydroxylamine and not by functional class nomenclature as in previous recommendations.
Therefore, the preferred IUPAC name of your example is (butan-2-ylidene)hydroxylamine.



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