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Guilherme Mazui

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What is the Difference Between Oxo and Formyl?

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The terms "oxo" and "formyl" refer to functional groups in organic molecules. The key difference between them is:

  • Oxo: Refers to a substitution of a single oxygen atom on a carbon atom by a double bond. It is typically associated with ketones, not aldehydes.
  • Formyl: Refers to the substitution of a three-atom HCO group onto a different carbon or other atom. It is often used as a substituent and is particularly associated with aldehydes.

When naming organic compounds, the choice between "oxo" and "formyl" depends on the specific structure and the priority of the functional groups. The prefix "formyl" is used in preferred IUPAC names, except for a -CHO group at the end of an acyclic chain. On the other hand, "oxo" is used when the functional group is a ketone.

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  • What is the Difference Between Oxo and Formyl?
  • Comparative Table: Oxo vs Formyl

    • Comparative Table: Oxo vs Formyl

    The main difference between "oxo" and "formyl" lies in the substitution and composition of the functional groups they represent. Here is a table summarizing the differences between "oxo" and "formyl":

    Feature Oxo Formyl
    Definition "Oxo" refers to a substitution of a single oxygen atom on a carbon atom by a double bond. "Formyl" refers to the substitution of a three-atom HCO group onto a different carbon or other atom.
    Functional Group Carbonyl (C=O). Aldehyde (CH=O).
    IUPAC Nomenclature Preferred in IUPAC names when the aldehyde carbon is not part of the longest continuous chain. For example, 4-formylhexanoic acid. Not always preferred, but sometimes used as a substituent. For example, 4-formylbenzoic acid.
    Examples 3-oxopentanal: An example where "oxo" refers to a ketone, not an aldehyde. Benzaldehyde: An example of a compound with a formyl group.

    In summary, "oxo" generally refers to a broader class of carbonyl compounds, while "formyl" specifically refers to aldehydes. The choice between using "oxo" or "formyl" depends on the molecule's structure, the functional group's priority, and the IUPAC nomenclature rules.

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    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.