Concept explainers
a)
Interpretation:
Whether D-erythrose and L-erythose are enantiomers or diastereomers has to be stated.
Concept Introduction:
Enantiomers are the compounds with same chemical formula. These are known as optical isomers. Enantiomers are basically stereo-isomers of the same compound. Two compounds are called enantiomers of each other if these are formed a non-superimposable mirror images.
Diastereomers are also the compounds with the same chemical formula. These are also the types of stereo-isomers. Two compounds are called diastereomers of each other if both the compounds have different configuration at the one or more (not all) equivalent stereo centers. These are not mirror images of each other.
b)
Interpretation:
Whether L-erythrose and L-threose, enantiomers or diastereomers are to be stated.
Concept Introduction:
Enantiomers are the compounds with same chemical formula. These are known as optical isomers. Enantiomers are basically stereo-isomers of the same compound. Two compounds are called enantiomers of each other if these are formed a non-superimposable mirror images.
Diastereomers are also the compounds with the same chemical formula. These are also the types of stereo-isomers. Two compounds are called diastereomers of each other if both the compounds have different configuration at the one or more (not all) equivalent stereo centers. These are not mirror images of each other.
Want to see the full answer?
Check out a sample textbook solutionChapter 20 Solutions
Organic Chemistry (8th Edition)
- O b. SN2 O c. E 2 d. SN1 О е. Е1 Label the pair of stereoisomers in Question 20 as either enantiomers, diastereomers or identical. a. Diastereomers O b. Enantiomers O C. Identical US PAGEarrow_forward9 A disaccharide consists of the molecules of D-glucose and D-glucosamine joined by a (1a, 1b)-glucosidic bond. a) Draw the structure of the disaccharide (Haworth projection) if you know that in D- glucose the anomeric carbon has an a-configuration. b) Give the name of the union you drew in question a. c) Draw the structure of the product (cantilever conformation) resulting from the effect of excess acetic anhydride and pyridine on the disaccharide. Hint: D-glucosamine has the same structure as D-glucose, but C-2 has an amino group instead of a hydroxyl.arrow_forwardIdentify the following monosaccharides as the D- or the L-isomer.arrow_forward
- A Fischer projection of a monosaccharide is shown below: CH2OH C=O H- = 2 HO- HO -OH H H CH₂OH Classify this monosaccharide (e.g., aldotriose) Does it have the D or L configuration?arrow_forwarda. How many stereogenic centers are present in α-D-galactose? b. Label the hemiacetal carbon in α-D-galactose. c. Draw the structure of β-D-galactose. d. Draw the structure of the polyhydroxy aldehyde that cyclizes to α- and β-D-galactose.arrow_forwardConsider the following compound, which is used by insects and some fungi to store energy:arrow_forward
- 1. Which of the following is not true to the monosaccharide below? H. ОН но- -H- но ОН ĆH2OH O It is the Fischer Projection of D-glucose. It is an aldohexose having 4 chiral centers and 24 stereoisomers. It is has a D-glucose because OH- group bonded to the highest numbered chiral C is pointing to the right. It is a polyhydroxy ketone having 8 enantiomeric pair.arrow_forwardHow many stereocenters are present in D-glucose? How many stereocenters are present in D-ribose? How many stereoisomers are possible for D-glucose? How many stereoisomers are possible for D-ribose?arrow_forwardi need an answer pleaseeeearrow_forward
- Consider only the top monosaccharide chair conformation. How would I draw the Fischer projection of the aldohexose from which this chair conformation is derived? And is the diaccharide shown reducing, non-reducing, or can that not be determined?arrow_forward14․ Identify the following as an ? or ? form and draw the Haworth structure of the other anomer. 15․ Below are the Fischer projections of monosaccharides.arrow_forwardconnected by an a, B-1,2-glycosidic bond. Explain why sucrose is both a and B at the same time. 4. Sucrose (table sugar) contains the monosaccharide glucose and the monosaccharide fructose CH2OH H. H H OH OH H ОН О HOH2C НО CH2OH OH H sucrosearrow_forward
- General, Organic, and Biological ChemistryChemistryISBN:9781285853918Author:H. Stephen StokerPublisher:Cengage LearningOrganic And Biological ChemistryChemistryISBN:9781305081079Author:STOKER, H. Stephen (howard Stephen)Publisher:Cengage Learning,Chemistry for Today: General, Organic, and Bioche...ChemistryISBN:9781305960060Author:Spencer L. Seager, Michael R. Slabaugh, Maren S. HansenPublisher:Cengage Learning
- Introduction to General, Organic and BiochemistryChemistryISBN:9781285869759Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar TorresPublisher:Cengage LearningChemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage Learning