
Concept explainers
Interpretation:
The Kiliani–Fischer reaction for the synthesis of epimeric aldoses is to be outlined and Fischer projection of
Concept introduction:
舧 A carbohydrate is a
舧
舧 Carbohydrates are oxidized by
舧 Aldaric acids are carbohydrates having two
舧 The molecules that are nonsuperimposable or not identical with their mirror images are known as chiral molecules.
舧 A pair of two mirror images that are nonidentical is known as enantiomers, which are optically active.
舧 The stereoisomers that are nonsuperimposable on each other and not mirror images of each other are known as diastereomers.
舧 The achiral compounds in which plane of symmetry is present internally and consists of chiral centres are known as meso compounds, but they are optically inactive.
舧 Compounds that have a plane of symmetry tend to exist in meso forms. A meso form arises when the two stereoisomers produce superimposable images, and hence, compounds having meso forms are optically inactive.
舧 The Kiliani-Fischer reaction is used for increasing the number of carbon atoms of the respective aldoses, thereby, lengthening the carbon chain of the compound. It is an effective and economic process for synthesizing monosaccharides through the hydrolysis of a cyanohydrin. Thus, it lengthens the carbon chain of the aldose by one carbon atom. It is used to produce epimers of higher aldoses from a lower aldose, that is, a single aldose produces a mixture of two diastereomeric sugars called epimers.

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Chapter 22 Solutions
Organic Chemistry
- Draw the skeletal ("line") structure of 2-hydroxy-4-methylpentanal. Click and drag to start drawing a structure. Xarrow_forwardDetermine whether the following molecule is a hemiacetal, acetal, or neither and select the appropriate box below. Also, highlight the hemiacetal or acetal carbon if there is one. hemiacetal acetal Oneither OHarrow_forwardWhat is the missing reactant R in this organic reaction? ་ ་ ་ ་ ་ ་ ་ ་ ་ ་ +R H3O+ • Draw the structure of R in the drawing area below. N • Be sure to use wedge and dash bonds if it's necessary to draw one particular enantiomer. Click and drag to start drawing a structure.arrow_forward
- Write the systematic name of each organic molecule: H structure H OH OH H OH name ☐ OHarrow_forwardDetermine whether each of the following molecules is a hemiacetal, acetal, or neither and select the appropriate box in the table. CH3O OH OH OH hemiacetal acetal neither hemiacetal acetal neither Xarrow_forwardWhat is the missing reactant R in this organic reaction? N N དལ་ད་་ + R • Draw the structure of R in the drawing area below. • Be sure to use wedge and dash bonds if it's necessary to draw one particular enantiomer. Click and drag to start drawing a structure. ㄖˋarrow_forward
- Draw the condensed structure of 4-hydroxy-3-methylbutanal. Click anywhere to draw the first atom of your structure.arrow_forwardUsing the bond energy values, calculate the energy that must be supplied or is released upon the polymerization of 755 monomers. If energy must be supplied, provide a positive number; if energy is released, provide a negative number. Hint: Avogadro’s number is 6.02 × 1023.arrow_forward-AG|F=2E|V 3. Before proceeding with this problem you may want to glance at p. 466 of your textbook where various oxo-phosphorus derivatives and their oxidation states are summarized. Shown below are Latimer diagrams for phosphorus at pH values at 0 and 14: Acidic solution -0.93 +0.38 -0.51 -0.06 H3PO4 →H4P206 H3PO3 H3PO2 → P→ PH3 -0.28 -0.50 → -0.50 Basic solution 3-1.12 -1.57 -2.05 -0.89 PO HPO →→H2PO2 P PH3 -1.73 a) Under acidic conditions, H3PO4 can be reduced into H3PO3 directly (-0.28V), or via the formation and reduction of H4P2O6 (-0.93/+0.38V). Calculate the values of AG's for both processes; comment. (3 points) 0.5 PH, 0.0 -0.5- 2 3 9 3 -1.5 -2.0 Pa H,PO H,PO H,PO -3 -1 0 2 4 Oxidation state, N 2 b) Frost diagram for phosphorus under acidic conditions is shown. Identify possible disproportionation and comproportionation processes; write out chemical equations describing them. (2 points) c) Elemental phosphorus tends to disproportionate under basic conditions. Use data in…arrow_forward
- These two reactions appear to start with the same starting materials but result in different products. How do the chemicals know which product to form? Are both products formed, or is there some information missing that will direct them a particular way?arrow_forwardWhat would be the best choices for the missing reagents 1 and 3 in this synthesis? 1. PPh3 3 1 2 2. n-BuLi • Draw the missing reagents in the drawing area below. You can draw them in any arrangement you like. • Do not draw the missing reagent 2. If you draw 1 correctly, we'll know what it is. • Note: if one of your reagents needs to contain a halogen, use bromine. Explanation Check Click and drag to start drawing a structure. 2025 McGraw Hill LLC. All Rights Reserved. Terms of Use | Priva ×arrow_forwardPredict the products of this organic reaction: Explanation Check IN NaBH3CN H+ ? Click and drag to start drawing a structure. D 5 C +arrow_forward
