Aldehydes and ketones Flashcards
What is the IUPAC naming system for an aldehyde?
Change suffix of parent alkane to -al.
What is the IUPAC naming system for a ketone?
Change suffix of parent alkane to -one and number from the direction that gives the carbonyl carbon the smaller number.
How do you name cyclic aldehydes where the cyclic structure is bonded directly to the carbonyl carbon?
the omlecule is named by adding the suffix -carbaldehyde (e.g. cyclohexanecarbaldehyde). The carbon of the ring that is attached to carbonyl carbon is carbon #1 when numbering.
How do you indicate a carbonyl group when there are multiple functional groups?
Use the infix -oxo-
What is a phenone?
A ketone in which one of the groups attached to the carbonyl carbon is a phenyl group.
How do you derive the common names of aldehydes?
Derived from carboxylic acids; drop the word acid and change the suffix -ic or -oic to -aldehyde.
How do you derive the common names of ketones?
Naming the two alkyl or aryl groups bonded to the carbonyl group as separate words, followed by the word ketone.
What is the common name for a 1 carbon aldehyde?
(Form)aldehyde
What is the common name for a 2 carbon aldehyde?
(Acet)aldehyde
What is the common name for a 3 carbon aldehyde?
(Propion)aldehyde
What is the common name for a 4 carbon aldehyde?
(Butyr)aldehyde
What is the common name for a 6 carbon aldehyde?
(Capro)aldehyde
The is the common name for a 3 carbon ketone?
Acetone
What is the common name for two phenyl groups attached to a carbonyl group?
Benzophenone
What is the common name for a phenyl group and a methyl group attached to a carbonyl group?
Acetophenone
What is he common name for two methyl groups attached to a carbonyl group?
Acetone
What is special about assigning alpha, beta, gamma (and so forth) to carbons in an aldehyde?
The carbonyl carbon can’t be substituted because there must be a hydrogen, so carbon adjacent to the C=O is the alpha carbon.
Rank the boiling points (lowest to highest) for the following 6 functional groups of similar molecular weights: alcohol, aldehyde, alkane, carboxylic acid, ether, ketone
- Ether
- Alkane
- Aldehyde
- Ketone
- Alcohol
- Carboxylic acid
Only which aldehyde(s) is/are miscible in water?
Methanal (formaldehyde) and Ethanal (acetaldehyde)
Only which ketone(s) is/are miscible in water?
Acetone
What is a carbohydrate?
A polyhydroxyaldehyde, a polyhydroxyketone or a substance that gives these compounds on hydrolysis.
Carbohydrate chemistry is essentialy the chemistry of what other functional groups?
The chemistry of hydroxyl groups and carbonyl groups and of the acetal bonds formed between these two functional groups.
What is a carbohydrate?
A carbohydrate that cannot be hydrolyzed to a simpler carbohydrate.
What is an aldose?
A monosaccharide containing an aldehyde group
What is a ketose?
A monosaccharide containing a ketone group.
How do you indicate that a compound is a carbohydate?
-ose
How do you indicate the number of carbons in a carbohydrate?
Tri-, Tetr-, pent-, hex-, hept-, oct-
What are the two trioses?
- Glyceraldehyde
2. Dihydroxyacetone
Draw glyceraldehyde (give IUPAC name)
2,3-dihydroxypropanal
Draw dihydroxyacetone (give IUPAC name)
1,3-dihydroxypropanone
What is the purpose of the D,L- configuration system?
D- and L- glyceraldehyde (enantiomers) serve as a reference points for the assignment of relative configuration to all other aldoses and ketoses.
What is the penultimate carbon?
The stereocenter furthest from the carbonyl group; the second to last carbon.
What is a D-monosaccharide?
A monosaccharide that, when written as a Fischer projection, has the -OH on its penultimate carbon to the right.
What is an L-monosaccharide?
A monosaccharide that, when written as a Fischer projection, has the -OH on its penultimate carbon to the left.
Draw the Fischer projection of D-glyceraldehyde
North: CHO
East: OH
South: CH2OH
West: H
Draw the Fischer projection of L-glyceraldehyde
North: CHO
East: H
South: CH2OH
East: OH
What do prefixes such as Rib-, arabin- and gluc- indicate?
The configuration of all other chiral enters in the monosaccharide.
What are the three most abundant hexoses in the biological world?
D-glucose, D-galactose, D-fructose
The disaccharide sucrose is composed of what two monosaccharides?
D-fructose and D-glucose
The disaccharide lactose is composed of what two monosaccharides?
D-galactose and D-glucose
The disaccharide maltose is composed of what two monosaccharides?
Two molecules of D-glucose
Draw the Fischer projection of D-glucose
CHO (Right, Right, Left, Right) H (-) OH HO (-) H H (-) OH H (-) OH CH2OH
Draw the Fischer projection of D-galactose
CHO (Right, Left, Left, Right) H (-) OH HO (-) H HO (-) H (Differs from glucose only at C-4) H (-) OH CH2OH
Draw the Fischer projection of D-Fructose
CH2OH (Right, Right, Left) C=O HO (-) H H (-) OH H (-) OH CH2OH
The terms alpha and beta refer to what carbon in carbohydrates?
Alpha and beta refer to the configuration at the anomeric carbon.
Define an anomeric carbon
The carbon that becomes a stereocenter from cyclic hemiacetal/acetal formation of a carbohydrate.
Define anomers
Carbohydrates that differ in configuration only at their anomeric carbons
What is a furanose?
A five-membered cyclic form of a monosaccharide
What is a pyranose?
A six-membered cyclic form of a monosaccharide