Diol
You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.
Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [1] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.
A diol or glycol is a chemical compound containing two hydroxyl groups (-OH groups). Vicinal diols have hydroxyl groups attached to adjacent atoms. Examples of vicinal diol compounds are ethylene glycol and propylene glycol. Geminal diols have hydroxyl groups bonded to the same atom. In general, organic geminal diols readily dehydrate to form a carbonyl group. For example, carbonic acid ((HO)2C=O) is unstable and has a tendency to convert to carbon dioxide (CO2) and water (H2O). Nevertheless, in rare situations the chemical equilibrium is in favor of the geminal diol. For example, when formaldehyde (H2C=O) is dissolved in water the geminal diol (H2C(OH)2) is favored.
Examples of diols in which the hydroxyl functional groups are more widely separated include 1,4-butanediol and bisphenol A.
Synthesis of diols
Because diols are a common functional group arrangement, numerous methods of preparation have been developed.
- Vicinal diols can be produced from the oxidation of alkenes, usually with dilute acidic potassium permanganate, also known as potassium manganate(VII). Using alkaline potassium manganate(VII) produces a colour change from clear deep purple to clear green; acidic potassium manganate(VII) turns clear colourless.
- Osmium tetroxide can similarly be used to oxidize alkenes to vicinal diols.
- A chemical reaction called Sharpless bishydroxylation can be used to produce chiral diols from alkenes using an osmate reagent and a chiral catalyst.
- Another method is the Woodward cis-hydroxylation.
- In the Prins reaction 1,3-diols can be formed in a reaction between an alkene and formaldehyde.
Reactions
- A diol reacts like an alcohol, such as esterification and ether formation.
- Diols such as ethylene glycol are used as co-monomers in polymerization reactions forming polymers including some polyesters and polyurethanes. A different monomer with two identical functional groups, such as a dioyl dichloride or dioic acid is required to continue the process of polymerization through repeated esterification processes.
- In glycol cleavage the C-C bond in a vicinal diol is cleaved with formation of two aldehyde groups.
See also
- Alcohols, chemical compounds with one hydroxyl group
- Triols, chemical compounds with three hydroxyl group
- Polyols, chemical compounds with multiple hydroxyl groupsde:Dioleit:Dioli
nl:Diol ja:グリコールfi:Dioli sv:Diol
Acknowledgement and Attribution Regarding Sources of Content
Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .
