Hydroxy Group
The -OH functional group.
R Groups
Indicate carbon groups; R&R can be the same or different groups.
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Hydroxy Group
The -OH functional group.
R Groups
Indicate carbon groups; R&R can be the same or different groups.
Alcohols
Have an -OH group attached to an aliphatic carbon (C-OH).
R-OH
General Formula of Alcohols
Phenols
Have an -OH group on a benzene ring (an aromatic alcohol).
C6H5OH
General Formula of Phenol
Ethers
Have the functional group C-O-C.
R-O-R
General Formula of Ether
large
Alcohols, Phenols, and Ethers are important organic compounds that occur naturally and are produced synthetically in ____ amounts.
Ethanol
(drinking alcohol) has been used since ancient times.
peppermint oil
Menthol is a ten-carbon alcohol found in __; it is used widely as a flavoring agent.
Cholesterol
An important biological molecule and has been implicated in some forms of heart disease.
H2O
Alcohols, phenols, and ethers may be considered to be derived from ____.
alkyl group
In alcohols one of water's hydrogens is replaced with an .
aromatic ring
In phenols one of water's hydrogens is replaced with an _.
both
In ethers of water's hydrogens are replaced with alkyl groups.
Alcohol Nomenclature
1.) Name the longest carbon chain to which the -OH group is attached. Use the hydrocarbon name of the chain, drop the final -e and replace it with -ol.
2.) Number the longest carbon chain to give the lowest number to the carbon with the attached -OH.
3.) Locate the -OH position and locate/name any other groups attached to the longest chain.
4.) Combine the name and location of other groups, the location of the -OH, and the longest chain into the final name.
common names
Some of the simpler alcohols are often known by ; in these names the alkyl group is followed by the word alcohol.
Phenol Nomenclature
Substituted are usually named as derivatives of the parent compound phenol.
chemistry
The of alcohols often depends on the groups bonded to the carbon with the hydroxy on it.
attached group
There are three classifications of alcohols; these classifications are based on the alcohol's .
Primary Alcohols
The carbon with the hydroxy group is attached to one other carbon atom and two hydrogen atoms.
Secondary Alcohols
The carbon with the hydroxy group is attached to two other carbon atoms and one hydrogen atom.
Tertiary Alcohols
The carbon with the hydroxy group is attached to three other carbon atoms and no hydrogens.
polar
The -OH group of alcohol is and capable of hydrogen bonding.
True
T or F: Hydrogen bonding in alcohols makes low molecular weight alcohols highly soluble in water.
alkane
As the size of the alkyl group in an alcohol increases, the physical properties become less water-like and more _-like.
hydrophobic
Larger alkanes have greater _ regions and are less soluble or insoluble in water.
Solubility Ratio
1 hydroxy for every 5 carbons.
carbon
The number of _ atoms per hydroxy group determines the solubility in water.
boiling point
Hydrogen bonding can affect __.
high
The -OH group in alcohol can hydrogen bond between alcohol molecules leading to relatively _ boiling points.
alcohols
When compared to molecules of similar molecular weight, have much higher boiling points.
Dehydration
The removal of water from an alcohol.
Dehydration to Produce an Alkene
(180 degrees C) An elimination reaction, uses Markovnikov's rule.
Elimination Reaction
A reaction when two or more bonds are broken to form a new multiple bond.
False
T or F: Only one product can be formed in dehydration to produce an alkene.
principle
The major/ alkene produced is the one in which the higher number of carbon groups is bonded to the double-bonded carbon atoms.
living systems
Alcohol dehydration is important in __.
Enzymes
_ (rather than sulfuric acid) are the catalysts in alcohol dehydration.
Dehydration to Produce an Ether
(140 degree C) A dehydration reaction occurs between two alcohol molecules where an -H is removed from one alcohol, an -OH group is removed from the other and they combine to make water. Leaving the two remaining fragments to bond.
Primary Alcohols
Ether-forming reactions are useful mainly with _.
living organisms
Dehydration synthesis is important in because it is part of the formation of carbohydrates, fats, proteins, and other essential substances.
temperature
The type of dehydration is controlled by .
Oxidation Reactions
When a molecule gains oxygen atoms or loses hydrogen atoms.
two
Alcohols can be oxidized by removing ____ hydrogen atoms.
oxidizing agents
Alcohol oxidations can be accomplished with an __ (O) such as K2Cr2O7 or KMnO4.
carboxylic acid
Primary alcohols --> aldehyde --> __
ketone
Secondary alcohols --> _
no reaction
Tertiary alcohols --> __
useful
Alcohols can be converted by chemical reactions into a wide variety of other products.
False
T or F: Most alcohols occur naturally in commercial quantities therfore they are prepared from alkenes.
Nature
_ also employs multistep reactions to carry out processes essential to life.
protonated alcohol
During alcohol dehydration mechanism, the H+ ion becomes bonded to the oxygen resulting in a _.
Methanol
(methyl alcohol) known as wood alcohol because historically it was produced by the distillation of wood. Useful as a solvent and industrial starting material due to its oxidation product formaldehyde. Highly toxic, can cause blindness.
CH3OH
Formula of Methanol
Ethanol
(ethyl alcohol, grain alcohol) the active ingredient in alcoholic beverages. Produced commercially from ethylene and through biological fermentation of carbohydrates. Used in pharmaceuticals as a solvent and in aftershave lotions as an antiseptic and skin softener. It is an important industrial starting material and used in fuels such as gasohol.
Gasohol
Mixture of gasoline and ethanol.
CH3CH2OH
Formula of Ethanol
2-Propanol
(isopropyl alcohol) the main component of rubbing alcohol. Acts as an astringent on the skin causing the skin tissue to contract, harden, and limit secretions. Lowers skin temperature by rapidly evaporating from the skin. It is extremely poisonous and shouldn't be taken internally.
1,2,3-Propanetriol
(glycerol or glycerin) has three hydroxy groups making it useful for many things. The hydrogen bonding resulting from the three hydroxy groups causes it to a syrupy/high-boiling point liquid with an affinity for water. Used as a food moistening agent, good for soaps, and to retain water that maintains the freshness of cut flowers.
1,2-Ethanediol
(ethylene glycol) high-boiling point liquid that is completely miscible with water (hydrogen bonding). Used as antifreeze and a starting material for the manufacture of polyester fibers.
1,2-Propanediol
(propylene glycol) high-boiling point liquid that is completely miscible with water (hydrogen bonding). Used as antifreeze and a starting material for the manufacture of polyester fibers.
colorless
Phenol is a , low-melting-point solid with a medicinal odor.
carbolic acid
Adding a small amount of water to Phenol causes the solid to liquefy (this mixture is commonly called _).
weak acids
Unlike alcohols, phenols behave as _ in water (these acids can chemically burn the skin).
salts
Phenols can also react with bases to form .
Joseph Lister
In the late 1800's an English surgeon named _ introduced phenols as a hospital antiseptic (before that time antiseptics were not used and few patients survived even minor surgeries).
4-chloro-3,5-dimethylphenol
Nonirritating topical antiseptic
4-hexylresorcinol
Used in mouthwashes and throat lozenges.
disinfectants
Some phenol derivatives are used as .
Lysol
O-phenylphenol and 2-benzyl-4-chlorophenol are the active ingredients in .
food
Some phenol derivatives are used as antioxidants in _.
Antioxidants
Agents that interfere with oxidizing reactions, protect food from spoilage and other unwanted reactions.
BHA & BHT
_ are widely used in the packaging materials for foods that might turn rancid (they are listed as food ingredient that "will maintain freshness").
Naming Ethers
Name the smaller of the two R groups as an alkoxy group attached to the parent chain by replacing the -yl ending of the R group with -oxy.
Common Names of Ethers
Name the groups attached to the oxygen alphabetically and add the word ether. If the groups are the same use the prefix di-.
Heterocyclic Rings
Contain atoms of elements other than carbon in the ring (many biological molecules have these rings).
carbohydrates
Many contain cyclic ethers.
Cyclic Ethers
Rings containing oxygen
Furan
Common cyclic ether:
Pyran
Common cyclic ether:
less
Ethers are much _ polar than alcohols because oxygen is bonded to two carbons rather than a hydrogen.
alkanes
Ethers can hydrogen bond to water, making them more soluble than _.
low
Ethers cannot hydrogen bond with other ethers, therefore they have ____ boiling and melting points and are less soluble in water than alcohols.
inert
Ethers are ____ and do not react with most reagents (like alkanes) making them a useful solvent.
flammable
Ethers are highly (like alkanes).
Thiols
Contain a sulfhydryl group (-SH).
6A
Sulfur and oxygen belong to the same group (___) on the periodic table so they react similarly.
analogous
The sulfhydryl group in thiols is to the hydroxy group in alcohols.
Disulfides
Compounds containing an -S--S- linkage.
odor
The most distinguishing characteristic of thiols is their strong and offensive _. Ex.) skunks, stink bugs, onions, garlic, etc.
flavors
Some thiols have less offensive odors and some are _.
1-propanethiol
The odor in freshly chopped onions.
1-propane-3-thiol
Responsible for the odor and flavor of garlic.
3,3-di-(1-propenyl)
disulfide is responsible for the odor and flavor of garlic.
Ethanethiol
(CH3CH2-SH) added to natural gas (methane) to make it possible to detect a gas leak.
Oxidizing Thiols
Forms disulfide (-S--S-) linkage.
General Formula: 2R -- SH + (O) ----> R--S--S--R + H2O
Disulfide Reduction
Oxidation reactions can be reversed with a reducing agent (H). The disulfides are uncoupled to produce thiols.
General Reaction: R--S--S--R + 2(H) ------> 2R--SH
Heavy Metal Reaction
Metal ions react with the sulfhydryl group.
General Reaction: 2R--SH + M2+ ------> R--S--M--S--R + 2H+