- A colorless, flammable, volatile liquid, CH3CH(OC2H5)2, used in cosmetics and as a solvent.
- Any of the class of compounds formed from aldehydes combined with alcohol.
Dictionary:
ac·e·tal (ăs'ĭ-tăl') ![]() |
| 5min Related Video: acetal |
| Sci-Tech Encyclopedia: Acetal |
A geminal diether (R1 = H). Ketals, considered a subclass of acetals, are also geminal diethers (R1 = C, aliphatic or aromatic). Acetals are (1) independent structural units or a part of certain biological and commercial polymers, (2) blocking or protecting groups for complex molecules undergoing selective synthetic transformations, and (3) entry compounds for independent organic chemical reactions. See also Polyacetal.
Acetals are easily prepared by the reaction of aldehydes with excess alcohol, under acid-catalyzed conditions. This is usually a two-step process (see reaction below) in which an aldehyde is

| Veterinary Dictionary: acetal |
An organic compound formed by a combination of an aldehyde with an alcohol.
| Wikipedia: Acetal |
An acetal is a molecule with two single bonded oxygens attached to the same carbon atom.
Traditional usages distinguish ketal from acetal (whereas the ketal has two carbon-bonded R groups, the acetal has one carbon-bonded R group as H-). Current accepted terminology classifies ketals as a subset of acetals.
The plastic known as acetal is a polyacetal.
Formation of an acetal occurs when the hydroxyl group of a hemiacetal becomes protonated and is lost as water. The carbocation ion that is produced is then rapidly attacked by a molecule of alcohol. Loss of the proton from the attached alcohol gives the acetal. Acetals are stable compared to hemiacetals but their formation is reversible as with esters. As a reaction to create an acetal proceeds, water must be removed from the reaction mixture or it will hydrolyse the product. The formation of acetals reduces the total number of molecules present and therefore is not favourable with regards to entropy. A way to improve this is to use an orthoester as a source of alcohol. Aldehydes and ketones undergo a process called acetal exchange with orthoesters to give acetals. Water produced along with the acetal product is used up in hydrolysing the orthoester and producing more alcohol to be used in the reaction.
Acetals are important in nature, for example in solution the most stable form of glucose is its cyclic hemiacetal and maltose is an acetal made from two glucose units. Acetaldehyde diethyl acetal is an important flavouring compound in distilled beverages.[1]
Acetals are sometimes used as protecting groups for carbonyl groups in organic synthesis as they are stable with respect to hydrolysis by bases.
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
| Translations: Acetal |
Nederlands (Dutch)
acetaal (chemische verbinding)
Deutsch (German)
n. - (chem.) Acetal
Ελληνική (Greek)
n. - (χημ.) ακετάλη
Português (Portuguese)
n. - acetal (m) (Quím.)
中文(简体)(Chinese (Simplified))
乙缩醛, 乙缩醛二乙醇
中文(繁體)(Chinese (Traditional))
n. - 乙縮醛, 乙縮醛二乙醇
日本語 (Japanese)
n. - アセタール, アセタール樹脂
العربيه (Arabic)
(الاسم) أسيتال : سائل طيار عديم اللون
עברית (Hebrew)
n. - תרכובת אורגנית שנוצרה מדחיסה של שתי פרודות אלכוהול עם פרודת אלדהיד, אצטאל (תרכובת)
If you are unable to view some languages clearly, click here.
To select your translation preferences click here.
| fucoside | |
| polyvinyl acetal | |
| acetal resins (organic chemistry) |
| What is acetic acid? Read answer... | |
| Is Acetate natural? Read answer... | |
| What is the symbol of acetate? Read answer... |
| Is Acetate in PVC? | |
| What is the formula for acetate? | |
| What is acetate paper? |
Copyrights:
![]() | Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved. Read more | |
![]() | Sci-Tech Encyclopedia. McGraw-Hill Encyclopedia of Science and Technology. Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved. Read more | |
![]() | Veterinary Dictionary. Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved. Read more | |
![]() | Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Acetal". Read more | |
![]() | Translations. Copyright © 2007, WizCom Technologies Ltd. All rights reserved. Read more |
Mentioned in