CHM 244; Miami University Middletown
First Semester (2013-2014)
Section MA – Dr. Janet Marshall
Section MB – Dr. Chuck Degenhardt
iPad IR Spectral Exercise
For each set of IR spectra (numbered IR1 – IR9), answer the following questions in your lab notebook.
You may find it helpful to touch and overlay the spectra as you work through each page.
IR1 Compounds:
Hexane (red)
1-Hexene (blue )
1-Hexyne (green)
Based on your comparison of the three spectra, how does the hybridization of the carbon affect the C-H
stretching frequency, υ(C-H)? In your answer, include approximate stretching frequency values in
wavenumbers, cm-1. Which υ(C-H) is higher in energy? Why?
How does the hybridization of the carbon affect the C-H bending vibrations, δ(C-H)?
The “fingerprint” region of the spectrum of an alkene can often tell you the substitution pattern of the
double bond. What absorption(s) in the spectrum of 1-hexene correlate with a mono-substituted alkene?
Are these absorptions due to stretching or bending vibrations?
Give an approximate value for the carbon-carbon double bond stretch for 1-hexene. Give an approximate
value for the carbon-carbon triple bond stretch for 1-hexyne. Which one is higher in energy? Why?
IR2 Compounds:
3-Hexanol (red)
Hexanal (green)
Hexanoic acid (blue)
Two of these compounds show a strong absorption corresponding to an O-H stretch, υ(O-H). What are
the two compounds and what is the frequency range of this absorption for each compound. Why are these
two absorptions so broad? Which one is higher in energy?
Two of these compounds show a strong absorption corresponding to the carbonyl stretch, υ(C=O). What
are these two compounds? Give an approximate stretching frequency for this absorption for each
compound.
Aldehydes typically show two absorptions corresponding to the stretching of the carbonyl
carbon/aldehyde hydrogen bond. Can you observe both of these in hexanal? It may be helpful to overlay
the hexanal and 3-hexanol spectra. Give approximate values for these two absorptions.
IR3 Compounds:
1-Hexyne (green)
3-Hexyne (red)
Both of these compounds have the same functional group. However, there are three key absorptions in
the spectrum of 1-hexyne which are not found in the spectrum of 3-hexyne. Give an approximate
frequency for each of these absorptions and assign them as bond stretches or bends. Be sure to include
which atoms are involved.
Why doesn’t 3-hexyne show an absorption for the carbon-carbon triple bond?
IR4 Compounds:
Cyclohexanone (red)
2-Cyclohexen-1-one (blue)
Comment on the similarities and differences between these two compounds in the C-H stretching region
of the spectrum. Give the frequencies and assign the stretches due to the sp3 C-H bonds and to the
sp2 C-H bonds.
Both compounds contain the ketone functional group, but the υ(C=O) stretching frequency differs.
Which one is lower in energy? Offer an explanation for the difference using resonance structures to
support your answer.
IR5 Compounds:
Acetamide (red)
N,N-Dimethylacetamide (blue)
Assign the two absorptions found above 3000 cm-1 in acetamide. Why are these absent in
N,N’-dimethylacetamide?
What would you expect to see in this spectral region for N-methylacetamide?
IR6 Compounds:
Ethylbenzoate (red)
Ethylacetate (blue)
Comment on the similarities and differences between these two compounds in the C-H stretching region
of the spectrum. Give the frequencies and assign the stretches due to the sp3 C-H bonds and to the
aromatic sp2 C-H bonds.
Both compounds contain the ester functional group, but the υ(C=O) stretching frequency differs. Which
one is lower in energy? Why?
Based on your comparison of the two spectra, which absorptions correspond to the υ(C=C) and the
δ(C-H) for the aromatic ring. Give an approximate frequency for both.
Assign the absorption for the carbon-oxygen single bond stretch, υ(C-O), for each compound.
IR7 Compounds:
Cyclohexyl methanol (red)
Benzyl alcohol (blue)
Phenylacetic acid (green)
All three of these compounds show an υ(O-H). Give the frequency ranges for this absorption for each.
Which two are similar and why?
Which absorptions in the spectrum of benzyl alcohol are due to the aromatic ring? Include the frequency
ranges for the aromatic υ(C-H) and υ(C=C). Aromatic compounds often show a set of weak overtone
bands between 1700-2000 cm-1. Do you observe these?
One of these compounds has a carbon-oxygen double bond. What spectral feature in which compound
can be assigned to this bond? Give an approximate frequency for this absorption.
Which compounds show absorptions for the carbon-oxygen single bond stretch, υ(C-O)? Give the
approximate frequency range for each compound.
Why is the υ(C-O) absorption lower in energy than the υ(C=O) absorption?
IR8 Compounds:
1-Butanol (red)
Diethyl ether (blue)
These two compounds are constitutional isomers. Prove this to yourself. For each compound, prepare a
table of key absorptions and assignments that let you differentiate and assign the two spectra correctly.
Follow the format you’ll use for the spectra of your unknowns.
IR9 Compounds:
1-Hydroxy-2-butanone (red)
Ethyl acetate (blue)
Butanoic acid (green)
These three compounds are constitutional isomers. How do you know? For each compound, prepare a
table of key absorptions and assignments that let you differentiate and assign the three spectra correctly.
Follow the format you’ll use for the spectra of your unknowns.
CHM 244; Miami University Middletown
First Semester (2013-2014)
Section MA – Dr. Janet Marshall
Section MB – Dr. Chuck Degenhardt
iPad Stereochemistry Extra Credit (10 points)
Open the 3-D image of each of the five molecular structures listed below using Chem3D. For each
structure, answer the following questions. In the images, Carbon is grey, Hydrogen is white, Oxygen is
red, Nitrogen is blue, and Sulfur is yellow.
Norepinephrine
Norepinephrine is a neurotransmitter secreted by the medulla of the adrenal gland. It is believed to play a
role in the regions of the brain that mediate emotional behavior. Norepinephrine has one chiral center.
The naturally-occurring stereoisomer is depicted in this image. From the 3-D image, draw this isomer,
show the correct projection about the chiral center, and assign its absolute configuration.
Nicotine
Nicotine is an alkaloid obtained from the tobacco plant. In small doses, it is an addictive stimulant. In
large doses it causes depression, nausea, vomiting, and even death. Nicotine has one chiral center; the
natural stereoisomer is depicted in this image. Locate the chiral center and assign its absolute
configuration.
Captopril
Captopril is a chiral drug which is sold as a single enantiomer. It is an effective inhibitor of angiotensinconverting enzyme (ACE), and as such, is used in the treatment of high blood pressure and congestive
heart failure. From the 3-D image, draw the structure of this stereoisomer, show the correct projection
about the two chiral centers, and assign the absolute configuration of each.
Albuterol
Albuterol is one of the most effective and prescribed antiasthma drugs. One of the enantiomers of
albuterol is considerably more effective in the treatment of asthma than the other. The more effective
stereoisomer is depicted in this image. Locate the chiral center and assign its absolute configuration.
Tartaric Acid
Tartaric acid is a colorless, crystalline compound found in grapes and other fruits and vegetables.
Tartaric acid contains two chiral carbons, but it only has 3 stereoisomers. Assign the absolute
configuration of both chiral centers in the depicted image. Is this isomer optically active? Why or why
not?
CHM 245, Miami University Middletown
Second Semester (2013-2014)
Name:
Date:
iPad Extra Credit Exercise (10 points)
The purpose of this exercise is to pilot several approaches/questions for assessing whether iPad 3-D
chemical representations improve students’ understanding of organic functional groups, molecular
structure and shape, hybridization, and stereochemistry.
For each structural image, a 2-D representation is provided, along with a typical question one might see
on an exam or homework problem. Please answer the question before viewing the 3-D iPad image and
then answer the question again after viewing the 3-D image.
Also, feel free to offer any ideas/feedback for assessing the effectiveness of using iPads in organic
chemistry as well as basic chemistry courses targeted to non-science majors.
Pre-iPad Exercise
1. Functional Group Identification for Aspartame
Circle and identify all of the organic functional groups in the structure of aspartame, shown below.
2. Hybridization and Geometry of the Nitrogen Atoms in Melatonin
On the structure shown below, indicate the hybridization and geometry of the two nitrogen atoms in
melatonin.
3. Hybridization and Geometry of the Nitrogen Atoms in Nicotine
On the structure shown below, indicate the hybridization and geometry of the two nitrogen atoms in the
naturally-occurring form of nicotine.
4. Absolute Configuration of the Chiral Centers in Captopril
On the structure shown below, circle the chiral centers in Captopril and indicate their absolute
configurations.
5. Nitrogen Atoms in Morphine, Serotonin, Quinine, and Troger’s Base – Resolved Stereogenic Centers
or Not?
For the following four compounds, identify the sp3-hybridized nitrogen atoms. Indicate whether these
atoms are stereogenic centers which are likely to be resolved, meaning that a particular configuration is
favored and a pure enantiomer can be isolated.
Morphine
Quinine
Serotonin
Troger’s Base
Post-iPad Exercise
1. Functional Group Identification for Aspartame
Circle and identify all of the organic functional groups in the structure of aspartame, shown below.
2. Hybridization and Geometry of the Nitrogen Atoms in Melatonin
On the structure shown below, indicate the hybridization and geometry of the two nitrogen atoms in
melatonin.
3. Hybridization and Geometry of the Nitrogen Atoms in Nicotine
On the structure shown below, indicate the hybridization and geometry of the two nitrogen atoms in the
naturally-occurring form of nicotine.
4. Absolute Configuration of the Chiral Centers in Captopril
On the structure shown below, circle the chiral centers in Captopril and indicate their absolute
configurations.
5. Nitrogen Atoms in Morphine, Serotonin, Quinine, and Troger’s Base – Resolved Stereogenic Centers
or Not?
For the following four compounds, identify the sp3-hybridized nitrogen atoms. Indicate whether these
atoms are stereogenic centers which are likely to be resolved, meaning that a particular configuration is
favored and a pure enantiomer can be isolated.
Morphine
Quinine
Serotonin
Troger’s Base
CHM F108 – Chemistry & Culture of Food
Spring Semester, 2013-2014
Due: Tuesday, March 4
Your Name __________________________
Date ______________
The Shape of Smell (20 points)
Background and Purpose:
Animals rely on the presence of odorants to find food, recognize predators, and avoid toxins. The sense
of smell is also used to communicate. While the human nose is not as acute as many other animals, it is
still capable of recognizing and remembering 10,000 different smells. The purpose of this exercise is to
investigate several interesting and familiar molecules found in natural flavorings, herbs, and spices.
In this exercise, you will be asked to draw structures and provide molecular formulas from an
examination of 3-dimensional chemical images loaded on an iPad. You’ll also be asked to identify
organic functional groups found in these compounds in order to develop an understanding of the types of
structural patterns associated with many herb and spice molecules.
Complete Structures, Skeletal Structures, and Molecular Formulas:
Since it is often tedious to explicitly show every atom in a molecular structure, we commonly draw
chemical structures using skeletal representations. In the figure shown below, the skeletal structure on the
left is a simplified representation of the complete structure on the right. In a skeletal structure, a carbon
atom is present at every point where a line (bond) either starts or ends or where two or more lines (bonds)
meet. Every carbon atom has four bonds around it; although, the bonds to the hydrogen atoms are rarely
shown. This means that a carbon atom which only has one line drawn to it must have three more bonds
or three hydrogen atoms also connected to it. If a carbon atom has two lines drawn to it, two more bonds
connected to hydrogen atoms are implied. A carbon with three bonds shown has an additional bond to
hydrogen which is not shown. In skeletal structures, all atoms other than carbon or hydrogen are
explicitly shown, as are any hydrogen atoms bound to heteroatoms (atoms other than carbon).
In the complete structure on the right, the solid triangles indicate that the atom or group is coming
towards the viewer from the plane of the paper. The dashed triangles indicate that the atom or group is
going away from the viewer into the plane of the paper. The geometric shape of a carbon with four single
bonds is tetrahedral. This type of representation is often used when drawing carbons having a specific
stereochemistry or spatial arrangement.
The molecular (or chemical) formula is simply a listing of the number of atoms of each type and is
written as C7H12O2 for the structure illustrated below. The chemical formula does not provide any
information about the “connectivity of atoms” in a molecule or compound.
H H
H
O
O
H
C
H
C
O
C
C
C
H
H
H
C
H
O
C
H
Figure 1: Skeletal and complete structural representation of Methyl cyclopentanoate.
H
H
For each of the following molecular compounds, locate the 3-dimensional image on the iPad and
answer the following questions. Use the provided samples of compounds, flavoring extracts, herbs,
and spices, to answer the “smell” questions. For the iPad images, carbon is shown in grey,
hydrogen is white, oxygen is red, nitrogen is blue, and sulfur is yellow.
1.
Benzaldehyde
Benzaldehyde is the major odorant molecule found in natural and artificial almond flavoring. Draw the
complete molecular structure of benzaldehyde and circle and label all functional groups. Also draw the
skeletal structure and give the molecular formula. Describe the smell of almond extract.
2.
Vanillin
Vanillin is the major odorant molecule found in natural and artificial vanilla flavoring. Draw the
complete molecular structure of vanillin, circle and label all functional groups, and give the molecular
formula. (Note that the iPad image of vanillin does not show any hydrogen atoms.) Describe the smell of
vanilla extract.
3.
Myrcene
Myrcene is a component of the essential oils of thyme, lemon grass, bay leaves, and hops. It is an
important intermediate used in the perfumery industry. Myrcene is believed to have an analgesic effect
and anti-inflammatory properties. Draw the skeletal structure of myrcene and label all functional groups.
Describe the smell of the sample of myrcene.
4.
Methyl salicylate
Methyl salicylate is an organic compound produced by many species of plants. It is commonly known as
oil of wintergreen. It is often used in liniments such as Bengay to treat joint and muscular pain. In the
body, it is metabolized into salicylates, including salicylic acid, a known NSAID (non-steroid antiinflammatory drug). Methyl salicylate is also used as an antiseptic in Listerine mouthwash. Draw the
complete molecular structure of methyl salicylate, circle and label all functional groups, and give the
molecular formula. (Note that the iPad image of methyl salicylate does not show any hydrogen atoms.)
Describe the smell of the sample of methyl salicylate.
5.
(+)-Limonene and (-)-Limonene
The compound limonene is found in two stereoisomeric forms known as (+)-limonene and (-)-limonene.
One form is primarily found in lemon and orange peels and has a noticeable citrus odor. Smell both
samples of limonene and determine which form has a citrus odor. Describe the odor of the other form.
Draw the skeletal structure of limonene. What functional group is found in this compound?
6.
(+)-Carvone and (-)-Carvone
The compound carvone is found in two stereoisomeric forms known as (+)-carvone and (-)-carvone. One
form is the principal constituent of the oil from caraway seeds and the other is found in spearmint. Both
carvones are used in the food and flavor industry. In fact, Wrigley’s Spearmint Gum is soaked in one of
the stereoisomers of carvone and powdered with sugar. What two functional groups are found in
carvone? Smell both samples of carvone and determine which form of the compound is found in caraway
seeds and which is found in spearmint.
7.
Eugenol
Eugenol is an oily liquid extracted from cloves, nutmeg, and cinnamon. It has a spicy, clove-like aroma
and is the main component in the essential oil extracted from cloves. Eugenol is used medicinally as a
local antiseptic and anesthetic. It is a key ingredient in Indonesian kretek (clove) cigarettes. Draw the
complete molecular structure of eugenol, circle and label all functional groups, and give the molecular
formula. (Note that the iPad image of eugenol does not show any hydrogen atoms.) The smell of cloves
will give you a good sense of the smell of pure eugenol. Describe this fragrance.
8.
Myristicin
Myristicin is a compound found in fresh nutmeg. Interestingly, the botanical name of the most important
commercial species of the nutmeg tree is Myristica fragrans. Myristicin is a psychoactive substance and
in large doses can induce convulsions, palpitations, and nausea. In the 19th century, nutmeg was used as
an abortifacient which led to numerous cases of nutmeg poisoning. Draw the skeletal structure of
myristicin and circle and label all functional groups.
9.
Curcumin
Curcumin is a key compound found in turmeric, a rhizomatous perennial plant of the ginger family,
Zingiberaceae. Curcumin has a distinctly earthy, slightly bitter, slightly hot peppery flavor and a
mustardy smell. It has been used in traditional Indian (Ayurvedic) medicine for thousands of years and is
currently in clinical trials for treatment of kidney and cardiovascular diseases and several types of cancer.
Draw the skeletal structure of curcumin and circle and label all functional groups.
10.
trans-Anethole
trans-Anethole is a key compound found in the essential oils of anise and fennel seeds (botanical family Apiaceae) and star anise (botanical family - Illiciaceae). It is only slightly soluble in water but exhibits a
high solubility in ethanol. This property causes certain anise-flavored liqueurs to become opaque when
diluted with water – the Ouzo effect. Anethole is also present in absinthe, a liquor with a reputation for
psychoactive effects. Draw both the complete molecular and skeletal structures of trans-anethole and
circle and label all functional groups. The odors of anise seed, fennel seed, and/or star anise will give you
a good sense of the fragrance of this compound. Describe this smell.
11.
trans-Cinnamaldehyde
trans-Cinnamaldehyde is the organic compound that gives cinnamon its odor and flavor. The essential oil
of cinnamon bark is about 90% trans-cinnamaldehyde. It is used as a flavoring agent for chewing gum,
ice cream, candy, and beverages. Cinnamaldehyde is also used as a fungicide and insecticide. Draw the
skeletal structure of trans-cinnamaldehyde and circle and label all functional groups. Also, give the
molecular formula for this compound. The smell of cinnamon sticks will give you a good sense of its
fragrance. Describe this odor.
12.
2-Propene-1-thiol and Propane-1-thiol
These two thiol compounds are pungent molecules found in garlic and onions, respectively. Draw the
complete molecular structure of both compounds. Also, give the molecular formula of each. Describe
the major difference between them. (Note that the iPad image of one of these molecules does not show
any hydrogen atoms.)
CHM 111L – Food Chemistry (special topic)
Miami University Middletown
Dr. Janet Marshall
Fall Semester, 2013
Your Name __________________________
Date ______________
Your Partner’s Name __________________
The Shape of Smell
Purpose:
Animals rely on the presence of odorants to find food, recognize predators, and avoid toxins. The sense
of smell is also used to communicate. While the human nose is not as acute as many other animals, it is
still capable of recognizing and remembering 10,000 different smells. The purpose of this lab is to
investigate some of the reasons molecules smell differently. You will also be asked to compare the
structures of selected compounds to observed physical properties, such as odor and physical form
(solid/liquid/gas).
Background:
In this lab, you will be asked to draw structures and provide chemical formulas from an examination of
both molecular models and 3-dimensional images loaded onto an iPad. Since it is often tedious to
explicitly show every atom, we commonly draw chemical structures using skeletal representations.
In the figure shown below, the structure on the left is a simplified representation of the complete structure
on the right. In a skeletal structure, a carbon atom is present at every point where a line (bond) either
starts or ends or where two or more lines (bonds) meet. Every carbon atom has four bonds around it;
although, the bonds to the hydrogen atoms are rarely shown. This means that a carbon atom which only
has one line drawn to it must have three more bonds or three hydrogen atoms also connected to it. If a
carbon atom has two lines drawn to it, two more bonds connected to hydrogen atoms are implied. A
carbon with three bonds shown has an additional bond to hydrogen, which is typically not shown. In
skeletal structures, all atoms other than carbon or hydrogen are explicitly shown, as are any hydrogen
atoms bound to the heteroatoms.
In the complete structure on the right, the solid triangles indicate that the atom or group is coming
towards the viewer from the plane of the paper. The dashed triangles indicate that the atom or group is
going away from the viewer into the plane of the paper. The geometric shape of a carbon with four single
bonds is tetrahedral. This type of representation is often used when drawing carbons having a specific
stereochemistry or spatial arrangement.
The molecular (or chemical) formula is simply a listing of the number of atoms of each type and is
written as C7H12O2 (for the structure illustrated below). The chemical formula does not provide any
information about the “connectivity of atoms” in a molecule or compound.
O
O
H H
H
H
C
H
C
O
C
C
C
H
H
H
C
H
O
C
H
H
H
Figure 1: Skeletal and complete structural representation of methyl cyclopentanoate.
Associated Reading: Basic Chemistry
(custom text pages 171-188;
additional information on pages 340-383)
On Food and Cooking (pages 387- 396; 431-433)
Activity #1 (4 points)
(A) Compare the smells of “McCormick Imitation Almond Flavoring” and artificial almond flavoring
prepared in the lab using benzaldehyde. Also smell natural almond extract and compare its smell to the
artificial flavorings. Do they smell the same?
Draw the complete structure of benzaldehyde (showing all atoms and bonds) and write its chemical
formula. What two functional groups are present in benzaldehyde? You may find it helpful to look at the
3-D image of this compound on the iPad.
Benzaldehyde
(B) Compare the smells of “Royal Imitation Vanilla Flavoring” and artificial vanilla flavoring prepared
in the lab using vanillin. Also smell natural vanilla extract and compare its smell to the artificial
flavorings. Do they smell the same?
Draw the complete structure of vanillin (showing all atoms and bonds) and write its chemical formula.
Circle and label all of the functional groups present in vanillin. You may also find it helpful to look at the
3-D image of this compound on the iPad. (Note that the iPad image does not show any hydrogen atoms.)
Vanillin
Answer the following questions:
1. What were the similarities between the natural extracts and the artificial flavorings?
2. What were the differences between the natural extracts and the artificial flavorings?
Activity #2 (3 points)
In this activity, the compounds citronellal and citronellol differ in terms of functional group. Examine the
molecular models provided and note your observations, as indicated. (Carbon atoms are either black or
gray, Oxygen is blue, and Hydrogen is white, when shown.) Smell each compound and answer the
following questions.
A1 and A2
Citronellal and Citronellol
1
2
3
4
Smell: exactly the same -------------------------------------- completely different
Guess the smells
A1
A2
Using the molecular models and the 3-D images on the iPad, draw either complete or skeletal structures
of the two compounds and give the corresponding molecular formulas.
Based on the functional groups, assign which structure (A1 or A2) is Citronellal and which is Citronellol.
(Hint: The “al” ending indicates an aldehyde and the “ol” ending signifies an alcohol.)
Which functional group is found in both compounds?
Give an example of a spice containing each compound and label each spice accordingly.
Activity #3 (6 points)
Each of the pairs of compounds in activity #3 differs in terms of the connectivity of atoms. The paired
compounds are called constitutional or structural isomers since they have the same molecular formula but
different connectivity. They may or may not have different functional groups. Examine the molecular
models provided for each set of compounds and note your observations as indicated. (Carbon atoms are
either black or gray, Oxygen is blue, and Hydrogen is white, when shown.) Where noted, smell each set
of chemicals and answer the following questions.
C1 and C2
(-)-Limonene and Myrcene
1
2
3
4
Smell: exactly the same -------------------------------------- completely different
Guess the smells
C1
C2
Using the molecular models and the 3-D images on the iPad, draw either complete or skeletal structures
of the two compounds and give the corresponding molecular formulas. Label your drawings as
C1 = (-)-Limonene and C2 = Myrcene.
Which functional group is found in both compounds?
Give an example of a spice containing each compound and label each spice accordingly.
E1 and E2
Geraniol and Linalool
1
2
3
4
Smell: exactly the same -------------------------------------- completely different
Guess the smells
E1
E2
Using the molecular models and the 3-D images on the iPad, draw either complete or skeletal structures
of the two compounds and give the corresponding molecular formulas. Label your drawings as
E1 = Geraniol and E2 = Linalool. (Note that the geraniol image on the iPad does not show any hydrogen
atoms.)
These compounds have the same two functional groups. What are they?
Give an example of a spice containing each compound and label each spice accordingly.
Activity #4 (9 points)
Each of the pairs of compounds in activity #4 differs in terms of the 3-dimensional arrangement of atoms.
The paired compounds are called stereoisomers since they have the same molecular formula and the same
connectivity of atoms but a different spatial arrangement of atoms. They have exactly the same
functional groups. Examine the molecular models provided for each set of compounds and note your
observations as indicated. (Carbon atoms are either black or gray, Oxygen is blue, and Hydrogen is
white, when shown.) Where noted, smell each set of chemicals and answer the following questions.
G1 and G2
cis-Oleic Acid and trans-Oleic Acid
Using the molecular models and the 3-D images on the iPad, draw either complete or skeletal structures
of the two compounds and give the corresponding molecular formula. Label your drawings as
G1 = cis-Oleic acid and G2 = trans-Oleic acid.
Compare the physical appearance of the two substances G1 and G2. Note your observations. Which
compound has the higher melting point?
What two functional groups are found in each of these compounds?
What do the prefixes cis and trans mean?
H1 and H2
(+)-Limonene and (-)-Limonene
1
2
3
4
Smell: exactly the same -------------------------------------- completely different
Guess the smells
H1
H2
Using the molecular models and the 3-D images on the iPad, draw either a complete or skeletal structure
of one of the two compounds and give the corresponding molecular formula.
Give three examples of spices containing either form of limonene.
I1 and I2
(+)-Carvone and (-)-Carvone
1
2
3
4
Smell: exactly the same -------------------------------------- completely different
Guess the smell(s)
I1
I2
Using the molecular models and the 3-D images on the iPad, draw either a complete or skeletal structure
of one of the two compounds and give the corresponding molecular formula.
What two functional groups are found in carvone?
One form of carvone is found in caraway seeds and the other is found in spearmint. Which form of
carvone is found in caraway seeds? Is it (+)- Carvone or (-)-Carvone? Use your nose to detect the
difference.
Activity #5 (3 points)
The two compounds in activity #5 have a common functional group but differ in terms of the molecular
formula. This functional group is often found in the molecular compounds that contribute to the flavor
and fragrance of many fruits and vegetables.
Examine the molecular models and note your observations as indicated. (In the molecular models,
Carbon atoms are either black or gray, Oxygen is blue, and Hydrogen is white, when shown) Where
noted, smell each set of chemicals and answer the following questions.
J1 and J2
Methyl salicylate and Methyl butyrate
1
2
3
4
Smell: exactly the same -------------------------------------- completely different
Guess the smell(s)
J1
J2
Using the molecular models and the 3-D images on the iPad, draw either a complete or skeletal structure
of each of the two compounds and give the corresponding molecular formulas. Label your drawings as
J1 = methyl salicylate and J2 = methyl butyrate. (Note that methyl salicylate is shown without hydrogen
atoms on the iPad image.)
One of these compounds is found in wintergreen oil and the other is found in pineapple oil. Match the
compounds with the oil.
What functional group is found in both compounds?