Inorganic chemistry, theacetoxy group (abbr.AcO– or–OAc;IUPAC name:acetyloxy^[1]), is afunctional group with theformula−OCOCH₃ and thestructure−O−C(=O)−CH₃. As the-oxy suffix implies, it differs from theacetyl group (−C(=O)−CH₃) by the presence of an additionaloxygen atom. The name acetoxy is the short form ofacetyl-oxy.

An acetoxy group may be used as a protection for an alcohol functionality in a synthetic route although the protecting group itself is called anacetyl group.

There are several options of introducing an acetoxy functionality in a molecule from an alcohol (in effect protecting the alcohol byacetylation):

• Acetyl halide, such asacetyl chloride in the presence of a base liketriethylamine^[2]
• Activated ester form of acetic acid, such as aN-hydroxysuccinimide ester, although this is not advisable due to higher costs and difficulties.^[3]
• Acetic anhydride in the presence of base with a catalyst such aspyridine with a bit ofDMAP added.^[4]

An alcohol is not a particularly strongnucleophile and, when present, more powerful nucleophiles likeamines will react with the above-mentioned reagents in preference to the alcohol.^[5]

For deprotection (regeneration of the alcohol)

• Aqueous base (pH >9)^[6]
• Aqueous acid (pH <2), may have to be heated^[7]
• Anhydrous base such as sodiummethoxide in methanol. Very useful when a methylester of a carboxylic acid is also present in the molecule, as it will not hydrolyze it like an aqueous base would. (Same also holds with an ethoxide in ethanol with ethyl esters)^[8]

• Acetate #Esters
• Acetyl group
• Acetylation

• Functional groups

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• Short description is different from Wikidata