{{Short description|Chemical compound}} [[File:Acetonide skeletal.svg|thumb|class=skin-invert-image|General structure of a 1,2-acetonide. The diol is shown in blue, the acetone part in red.]]
In organic chemistry, an '''acetonide''' is the functional group composed of the cyclic ketal of a diol with acetone. The more systematic name for this structure is an isopropylidene ketal. Acetonide is a common protecting group for 1,2- and 1,3-diols.<ref>{{cite book |title= Protecting Groups |last= Kocieński |first= Philip j. |year= 1994 |publisher= Thieme Medical Publishers |series= Foundations of Organic Chemistry Series |chapter= 3.2.2: Diol Protecting Groups—Acetals—Isopropylidene Acetals |page=103}}</ref> The protecting group can be removed by hydrolysis of the ketal using dilute aqueous acid.
==Example== The acetonides of small di- and triols, as well as many sugars and sugar alcohols, are common.<ref>{{cite journal|author1=Rychnovsky, S. D.|author2=Rogers, B. N.|author3=Richardson, T. I. |title=Configurational Assignment of Polyene Macrolide Antibiotics Using the [13c]Acetonide Analysis|journal=Acc. Chem. Res.|year=1998|volume=31|pages=9–17|doi=10.1021/AR960223N}}</ref> The hexaol mannitol reacts with 2,2-dimethoxypropane to give the bis-acetonide, which oxidizes to give the acetonide of glyceraldehyde:<ref>{{cite journal|title=D-(R)-Glyceraldehyde Acetonide|author1=Christopher R. Schmid|author2=Jerry D. Bryant|journal=Org. Synth.|year=1995|volume=72|page=6|doi=10.15227/orgsyn.072.0006}}</ref><ref>{{cite journal|title=L-(S)-glyceraldehyde Acetonide |author1=Christian Hubschwerlen|author2=Jean-luc Specklin|author3=J. Higelin|journal=Org. Synth.|year=1995|volume=72|page=1|doi=10.15227/orgsyn.072.0001}}</ref>
:(CHOHCHOHCH<sub>2</sub>OH)<sub>2</sub> + 2 (MeO)<sub>2</sub>CMe<sub>2</sub> → (CHOHCHCH<sub>2</sub>O<sub>2</sub>CMe<sub>2</sub>)<sub>2</sub> + 4 MeOH :(CHOHCHOCH<sub>2</sub>OCMe<sub>2</sub>)<sub>2</sub> + [O] → 2 OCHCHCH<sub>2</sub>O<sub>2</sub>CMe<sub>2</sub> + H<sub>2</sub>O
An example of its use as a protecting group in a complex organic synthesis is the Nicolaou Taxol total synthesis. It is a common protecting group for sugars and sugar alcohols, a simple example being solketal.
The acetonides of corticosteroid are used in dermatology, because their increased lipophilicity leads to better penetration into the skin.<ref>{{cite book|title=Medizinische Chemie|page=337|last1=Steinhilber|first1=D|last2=Schubert-Zsilavecz|first2=M|last3=Roth|first3=HJ|publisher=Deutscher Apotheker Verlag|location=Stuttgart|year=2005|isbn=3-7692-3483-9|language=German}}</ref><ref>{{cite journal|author1=Derendorf, H.|author2=Hochhaus, G.|author3=Meibohm, B.|author4=Mollmann, H.|author5=Barth, J.|title=Pharmacokinetics and Pharmacodynamics of Inhaled Corticosteroids|journal=J. Allergy Clin. Immunol.|year=1998|volume=101|pages=S440-S446|doi=10.1016/S0091-6749(98)70156-3|doi-access=free}}</ref>
* Fluclorolone acetonide * Fluocinolone acetonide * Triamcinolone acetonide
==See also== * Acetophenide * Acroleinide * Aminobenzal * Cyclopentanonide * Pentanonide
==References== {{Reflist|2}}
Category:Acetonides
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