Quiz - Carbohydrates - 3 | Carbohydrates
Organic Chemistry 3 - Quiz - Carbohydrates - 3
Which Fischer projection represents an aldotetrose?
An aldotetrose is a four-carbon sugar with an aldehyde group at the first carbon. Fischer projection is used to represent sugars in a two-dimensional plane, and aldotetroses have only four carbon atoms.
In naming monosaccharides, what does the suffix '-ose' denote?
The suffix '-ose' is used in carbohydrate nomenclature to indicate that the compound is a sugar, regardless of chain length or the presence of other functional groups.
How many stereoisomers are possible for aldopentoses?
Aldopentoses have three chiral centers, leading to 8 possible stereoisomers (23 = 8).
What is the consequence of mutarotation in monosaccharides?
Mutarotation is the change in optical rotation resulting from the equilibrium between different anomers of a sugar as it cyclically opens and closes. It does not alter the ring size or the aldehyde/ketone status.
What is the major reason for obtaining a mixture of α and β anomers during glycoside formation?
The mixture of α and β anomers in glycoside formation arises from the ability of the alcohol to attack the carbocation intermediate from both faces of its planar structure.
In the reduction of monosaccharides, what is the functional group transformation of the carbonyl group?
During the reduction of monosaccharides, an aldehyde group is reduced to form a primary alcohol, while ketone groups are reduced to form secondary alcohols. These reactions both end in the formation of an alditol (a primary alcohol).
In the Wohl degradation, what functional group is formed initially when hydroxylamine (NH2OH) adds to the carbonyl group of the aldose?
The initial step of the Wohl degradation involves the formation of an oxime when hydroxylamine adds to the carbonyl group of the aldose.
What is the reverse mechanism of the Kiliani-Fischer synthesis, involving the conversion of an aldose into a shorter-chain aldose?
The Wohl degradation involves the reverse mechanism of the Kiliani-Fischer synthesis, converting an aldose into a shorter-chain aldose.
How does the transition from a Fischer projection to a Haworth projection affect the depiction of hydroxyl groups?
In converting from a Fischer projection to a Haworth projection, groups that were on the right in the Fischer projection are drawn down in the Haworth, while those on the left are drawn up.
In the Williamson ether synthesis of monosaccharides, what is used as a mild base to deprotonate the alcohols?
Ag2O is used as a mild base in the Williamson ether synthesis to deprotonate the alcohols.