Chemical characterization and physical properties of solvents derived from epoxidized methyl soyate

Article abstract of DOI:10.1007/s11746-015-2607-6

Reactions of epoxidized methyl soyate (EMS) with alcohols, carbon dioxide, and acetone yielded liquids with solvent properties that make them more suitable than methyl soyate for dissolving polar substances. The reactions of EMS in the presence of Amberlyst-15 with alcohols, including methanol, ethanol, n-butanol, and 2-methoxyethanol, produced a series of solvents containing ether (-OR) and alcohol (-OH) groups. Reactions of EMS with carbon dioxide and acetone gave products with carbonate and ketonide functional groups, respectively. The complex mixture of compounds present in the product, EMS(MeOH), resulting from the reaction of EMS with MeOH, was characterized by MS and NMR investigations. In addition to products resulting from MeOH addition across the epoxide ring, were major amounts of cyclic tetrahydrofuran derivatives that were derived from reactions of methyl linoleate (18:2) with MeOH. All of the solvents were characterized by high boiling points and low vapor pressures. Their viscosities were higher than that of methyl soyate. Especially notable were their very high Kauributanol values, which ranged from 280 to 852, all of which are much higher than that (57) of methyl soyate. Such high KB values indicate that these solvents have very favorable solubilizing properties, which is illustrated by the ability of EMS(MeOH) to readily dissolve both polar (e.g., MeOH) and non-polar (e.g., hexane) compounds.

Full text of DOI:10.1007/s11746-015-2607-6

J Am Oil Chem Soc
DOI 10.1007/s11746-015-2607-6
ORIGINAL PAPER
Chemical Characterization and Physical Properties of Solvents
Derived from Epoxidized Methyl Soyate
Sean J. Riley · John G. Verkade · Robert J. Angelici
Received: 5 November 2014 / Revised: 26 January 2015 / Accepted: 28 January 2015
© AOCS 2015
Abstract Reactions of epoxidized methyl soyate (EMS)
with alcohols, carbon dioxide, and acetone yielded liq-
uids with solvent properties that make them more suit-
able than methyl soyate for dissolving polar substances.
The reactions of EMS in the presence of Amberlyst-15
with alcohols, including methanol, ethanol, n-butanol, and
2-methoxyethanol, produced a series of solvents contain-
ing ether (–OR) and alcohol (–OH) groups. Reactions of
EMS with carbon dioxide and acetone gave products with
carbonate and ketonide functional groups, respectively.
The complex mixture of compounds present in the prod-
uct, EMS(MeOH), resulting from the reaction of EMS with
MeOH, was characterized by MS and NMR investigations.
In addition to products resulting from MeOH addition
across the epoxide ring, were major amounts of cyclic tet-
rahydrofuran derivatives that were derived from reactions
of methyl linoleate (18:2) with MeOH. All of the solvents
were characterized by high boiling points and low vapor
pressures. Their viscosities were higher than that of methyl
soyate. Especially notable were their very high Kauri-
butanol values, which ranged from 280 to 852, all of which
are much higher than that (57) of methyl soyate. Such high
KB values indicate that these solvents have very favorable
solubilizing properties, which is illustrated by the ability of
EMS(MeOH) to readily dissolve both polar (e.g., MeOH)
and non-polar (e.g., hexane) compounds.
Keywords Soybean oil · Methyl soyate · Epoxidized
methyl soyate · Epoxidized soybean oil · Methyl linoleate ·
Solvents · Solubility · Amberlyst-15 · Kauri butanol · LC
APCI
Abbreviations
ESO
Epoxidized soybean oil
EMS
Epoxidized methyl soyate
FAME
mCPBA
NMR
LC–MS
APCI
TBAB
KB
Fatty acid methyl ester(s)
meta-chloroperbenzoic acid
Nuclear magnetic resonance spectroscopy
Liquid chromatography-mass spectrometry
Atmospheric pressure chemical ionization
Tetra(n-butyl)ammonium bromide
Kauri-butanol
VOC
Volatile organic compound(s)
Cr(acac)3 Chromium tris-acetylacetonate
Introduction
Although methyl soyate is used primarily as a biodiesel fuel
[1, 2], it is also used as a solvent in a variety of applications
such as parts cleaning, paint strippers, and removers/cleaners
[3, 4]. Methyl soyate (MS) has a low vapor pressure (<0.1 mm
Hg), a viscosity of 3.9–4.3 cSt, and a reported Kauri-butanol
value of 58 [5, 6]. Its advantages over conventional solvents
are biodegradability, low VOC, and low toxicity [5, 6]. How-
ever, one of its main disadvantages as a solvent is its very non-
polar nature, which means that it is most useful for dissolv-
ing non-polar substances. A goal of the present project was to
modify methyl soyate in ways that would render it as a suit-
able solvent for more polar substances. To this end, we sought
to introduce oxygen-containing groups into the hydrocarbon
chain of the unsaturated fatty acids in methyl soyate.
Electronic supplementary material The online version of this
article (doi:10.1007/s11746-015-2607-6) contains supplementary
material, which is available to authorized users.
S. J. Riley · J. G. Verkade · R. J. Angelici (*)
Department of Chemistry, Gilman Hall, Iowa State University,
Ames, IA 50011–3111, USA
e-mail: angelici@iastate.edu
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J Am Oil Chem Soc
Although there is some evidence that alcohols can be
added directly across double bonds in the unsaturated fatty
acids in methyl soyate [7], the conditions (concentrated sul-
furic acid at elevated temperature) are harsh and impracti-
cal for commercial production. The direct addition of meth-
anol across the double bonds of methyl linoleate (18:2) and
methyl oleate (18:1) using BF3·MeOH as the Lewis acid
catalyst is also known [8], but a large excess of the costly
and difficult-to-recover BF3·MeOH reagent is required.
In exploratory studies, we used a variety of acid catalysts
(p-toluenesulfonic acid, iron(III) chloride, Nafion SAC-13,
and Amberlyst-15) to catalyze the reaction of methyl soy-
ate with methanol. However, only trace amounts of prod-
ucts resulting from the addition of methanol across the dou-
ble bonds were detected.
We therefore activated the methyl soyate double bonds
by converting them to their corresponding epoxides, which
are known to react with alcohols to give products that con-
tain alkoxy, and hydroxy groups [9, 10]. Our strategy was
to convert methyl soyate (MS) to epoxidized methyl soy-
ate (EMS), which would then be reacted with alcohols,
CO2, and acetone (Scheme 1). All of these types of reac-
tions of EMS have been reported previously (see “Results
and Discussion” section). Extensive 1H and 31P NMR, mass
spectrometric, and chromatographic studies were used to
establish the molecular species present in several of the
solvents. The product resulting from the reaction of EMS
with methanol, using epoxidized soybean oil as the start-
ing material, was prepared on a relatively large scale (1.0
L). Physical properties (i.e., Kauri-butanol values, boiling
points, melting points, solubilities of water in them, and
viscosities) were determined for the products resulting
from the reactions of EMS with alcohols, carbon dioxide,
and acetone. Of particular relevance to the solvent proper-
ties of these liquids are their unusually high Kauri-butanol
values, which range from 280 to 852, all of which are much
higher than that of methyl soyate (57).
Experimental Section
Materials
All starting materials were commercially available
unless otherwise noted. Epoxidized soybean oil (ESO)
was supplied by Arkema and ChemCeed. High-oleic
soybean oil (HOSO) was supplied as Frymax by Stra-
tas Foods LLC. Methyl oleate (18:1) (>70 %), Amber-
lyst-15 (hydrogen form, dry, 18–23 mesh, 4.7 equiv
–SO3H/kg), tetra(n-butyl)ammonium bromide, 2-meth-
oxyethanol, phosphorus trichloride, pinacol, and tri-
ethylamine were purchased from Sigma-Aldrich.
Amberlyst-15 was activated by heating in an oil bath at
100 °C for 24 h under vacuum (1 Torr) and stored under
a nitrogen atmosphere prior to use. Methyl linoleate
(18:2, >95 %) and methyl linolenate (18:3, >70 %) were
purchased from TCI America. All reactions were con-
ducted under a nitrogen atmosphere, except where indi-
cated otherwise. The kinematic viscosities and Karl Fis-
cher water contents of the solvents were determined by
Galbraith Laboratories, Inc.
Kauri-butanol values were determined according to the
ASTM D1133 standard using a standardized Kauri-butanol
solution obtained from Lab Express International (Fair-
field, NJ). The A and B values provided by the supplier
were 104.8 and 38.2, respectively.
Liquid Chromatography–Mass Spectrometry (LC–APCI)
LC–MS experiments were performed on an Agilent QTOF
6540 accurate mass MSMS instrument with an atmospheric
pressure chemical ionization (APCI) ion source. HPLC
experiments employed a C18 reversed-phase column
(1.8 µm particle size, 4.6 × 50 mm) and 1-μL injection.
The solvent phase was 85 % MeOH/15 % H2O at a flow
rate of 0.8 mL/min.
Scheme 1 Preparation of sol-
vents from methyl soyate
RO
R1
OH
R2
EMS(ROH)
EMS(CO2)
ROH
CO2
O
O
O
O
R1
R2
R1
R2
R1
R2
epoxidized methyl soyate
(EMS)
methyl soyate
(MS)
Me2C=O
O
O
EMS(Me2CO)
R2
R1
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J Am Oil Chem Soc
1
NMR Data Collection
transparent liquid. H-NMR analysis of the liquid showed
that ESO was completely converted to EMS.
1H- and 13C-NMR spectra of samples dissolved in CDCl3
were obtained on Varian VXR-300 and -400 instruments.
31P-NMR spectra were collected on a Bruker AVIII-600
instrument with a relaxation delay time of 3 s.
Preparation of EMS from ESO, 1.0-L Scale
A procedure similar to that used for the 10-mL scale pro-
cedure (above) was followed for the conversion of ESO to
EMS on a 1.0-L scale. In a 5-L three-necked round-bottom
flask equipped with two reflux condensers, 1.0 L of ESO
was mixed with methanol (ca. 1 L) under a flowing nitrogen
atmosphere. The reaction mixture was heated to 60 °C in
order to dissolve the ESO. Solid NaOMe (10 g) was added
to the reaction mixture, which was allowed to react while
heating at 60 °C and stirring with a paddle stirrer for 1 h.
The solution was then allowed to cool to room temperature,
and the methanol was removed using a rotary evaporator.
The glycerol by-product, containing dissolved NaOMe,
was then removed from the desired product using a sepa-
Epoxidation of Methyl Linoleate (18:2) to E18:2
Methyl linoleate (1.0 mL, 3.0 mmol) was dissolved in
CH2Cl2 (10 mL) in a round-bottom flask at 0 °C. To this
solution was added mCPBA (1.4 g, 6.4 mmol), and then the
reaction mixture was stirred with a magnetic stir bar and
allowed to gradually warm to room temperature. After 16 h,
the solution was diluted with CH2Cl2 and washed with aque-
ous NaHCO3 solution. The organic phase was dried with
MgSO4 and concentrated in a rotary evaporator to afford
crude E18:2. The product was purified by flash silica gel
chromatography (4:1 hexanes/ethyl acetate as the solvent
phase, column size 20 × 2.5 cm) to give E18:2 as a clear
liquid (960 mg, 2.9 mmol, 97 % yield). The NMR spectrum
of this compound matches that reported in the literature [11].
1
ratory funnel to afford EMS. Analysis by H-NMR spec-
troscopy showed complete conversion of the ESO to EMS
based on the absence of peaks for the glycerol protons.
Reactions of Epoxides with Alcohols: a Typical Procedure
Epoxidation of Methyl Linolenate (18:3) to E18:3
The epoxide (E18:1, E18:2, E18:3, or EMS, ca. 1 mL) was
dissolved in 50 mL of methanol in a round-bottom flask
with a magnetic stirrer. To this was added 0.1 g of acti-
vated Amberlyst-15. The mixture was heated to 60 °C for
4 h with stirring under a nitrogen atmosphere, and then it
was allowed to cool to room temperature after which the
catalyst was separated by filtration. The methanol was then
removed with a rotary evaporator followed by removal of
a yellow coloration from the resulting product by dissolv-
ing it in an equal volume of hexanes followed by treat-
ment with ca. 1 g of decolorizing carbon. The carbon was
removed by filtration through a pad of Celite, and the hex-
anes were removed using a rotary evaporator. The result-
ing product was purified by flash silica-gel chromatography
(4:1 hexanes/ethyl acetate) to give the product as a light
yellow liquid. Characterizations of the products are dis-
cussed in the “Results and Discussion” section.
The epoxidation of 18:3 was performed in the same man-
ner as described for the epoxidation of 18:2, except that 3.1
equivalents of mCPBA per mol of 18:3 (1.0 mL, 3.1 mmol)
were used. The reaction conditions and workup procedure
were the same as for E18:2, including purification by flash
silica gel chromatography (1.02 g, 3.0 mmol, 97 % yield). 1H
NMR (300 MHz, CDCl3): δ 3.65 (s, 3H, CO2CH3), 3.21–3.03
(3H), 3.01–2.88 (3H), 2.29 (t, J = 6 Hz, 2H, CH2CO2), 1.82–
1.70 (4H), 1.68–1.21 (14H), 1.06 (t, J = 6 Hz, 3H); 13C NMR
(400 MHz, CDCl3): δ 176.93, 57.20, 56.12, 54.49, 54.41,
54.29, 54.22, 51.68, 34.68, 29.51, 29.38, 29.23, 28.11, 27.99,
26.75, 26.66, 25.10, 21.37, 10.70; HRMS: (APCI) m/z calcu-
lated for C19H32O5 341.2323, found 341.2312 (MH+).
Preparation of EMS from ESO, 10-mL Scale
In a procedure similar to that reported in reference [11],
10 mL of ESO was mixed with 50 mL of methanol in a
round-bottom flask under a flowing nitrogen atmosphere.
The reaction mixture was heated to 60 °C in order to dis-
solve the ESO. At this point, 0.10 g of solid NaOMe was
added to the reaction mixture, which was allowed to react
by heating at 60 °C and stirring with a magnetic stir bar
for 1 h. The solution was then allowed to cool to room
temperature, and the methanol was removed with a rotary
evaporator. The glycerol by-product, containing dissolved
NaOMe catalyst, was then removed from the desired prod-
uct using a separatory funnel to afford EMS as a colorless,
For larger scale conversions of EMS to EMS(MeOH),
e.g., 1.0 L, a similar procedure was followed using equal vol-
umes of EMS and MeOH with a paddle stirrer operating at a
speed of 180–200 rpm. The EMS(MeOH) was characterized
as discussed in the “Results and Discussion” section.
EMS(EtOH) was prepared using the same procedure as
for the preparation of EMS(MeOH) using ethanol as the
alcohol reactant. Excess ethanol was removed by rotary
evaporation. The characterization of this product is dis-
cussed in the “Results and Discussion” section.
EMS(HOCH2CH2OCH3) was prepared in the same
manner as EMS(MeOH) using 2-methoxyethanol as the
1 3

J Am Oil Chem Soc
O
O
alcohol. The excess 2-methoxyethanol was removed via
vacuum distillation (60 °C, 1 Torr).
O
E18:1
Carboxylation of EMS
MeOH, 60 ºC, 4 h
Amberlyst-15
In a procedure similar to that reported in reference [12],
EMS (100 mL) and TBAB (10 g) were combined in a
200 mL Parr bomb reactor. The vessel was sealed and
charged with 150 psi of carbon dioxide. The reaction mix-
ture was heated to 120 °C for 16 h with paddle stirring at
120 rpm. The reaction was then cooled to room tempera-
ture, and the reaction vessel was depressurized in a hood.
The resulting mixture was then dissolved in diethyl ether
(200 mL), and the organic solution was washed with water
to remove the TBAB. The ether was removed by rotary
evaporation to give EMS(CO2) as an orange liquid, which
was characterized as described in the “Results and Discus-
sion” section.
OMe
O
(A)
O
OH
+
OH
O
(A)
O
OMe
Scheme 2 Reaction of E18:1 with methanol
Preparation of EMS Acetonide, EMS(Me2CO), from EMS
both triethylamine (0.05 mL, 0.85 mmol) and the chloro-
phospholane (0.05 mL, 0.31 mmol). Finally, 1–2 mg of
Cr(acac)3 was added to the mixture as an NMR relaxation
reagent. The mixture was shaken and allowed to stand at
room temperature for 30 min before analysis by 31P-NMR
spectroscopy.
The acetonide EMS(Me2CO) was prepared from EMS and
acetone using a literature procedure [13]. The 1H- and 13C-
NMR spectroscopic data for the product match those in the
literature.
NMR and Mass Spectroscopic Data for the Compounds
and Mixtures (Structures of Compounds are given in
Schemes 2, 4, and 5)
31P‑NMR Experiments on Products Derivatized
with a Chlorophospholane
As described in the “Results and Discussion” section,
the presence of –OH groups in products resulting from
reactions of alcohols with the epoxides was detected
and quantitated by 31P-NMR spectroscopy after deri-
vatizing them with the chlorophospholane reagent
2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane
[14–16]. This reagent was prepared according to the fol-
lowing modified literature procedure [14]. In an oven-
dried round-bottom flask, pinacol (2.7 g, 23 mmol) was
dissolved in 10 mL of dry diethyl ether under a nitro-
gen atmosphere. To this solution was added phosphorus
trichloride (2.0 mL, 23 mmol) and pyridine (3.7 mL,
46 mmol) at 0 °C. The mixture was stirred for 4 h, while
allowing it to warm to room temperature. The ether sol-
vent was removed with a rotary evaporator, and the
chlorophospholane product was distilled under vacuum
(100 °C, 1 Torr) to give the desired reagent. The com-
pound was stored under nitrogen at 0 °C.
Methyl 10-hydroxy-9-methoxyoctadecanoate (A). 1H NMR
(300 MHz, CDCl3): δ 3.65 (s, 3H, CO2CH3), 3.47 (m, 1H),
3.40 (s, 3H, OCH3), 2.97 (m, 1H), 2.29 (t, J = 7 Hz, 2H,
CH2CO2), 1.63–1.24 (26H), 0.85 (t, J = 7.5 Hz, 3H); 13C
NMR (400 MHz, CDCl3): δ 174.50, 84.52, 84.48, 82.28,
72.83, 58.32, 56.13, 51.67, 34.31, 33.62, 32.11, 30.21,
30.12, 29.99, 29.76, 29.49, 29.41, 29.31, 25.98, 25.91,
25.14, 22.89, 14.33; HRMS: (APCI) m/z calculated for
C20H40O4 345.2999, found 345.2993 (MH+).
Methyl
8-[3-hydroxy-5-(1-methoxyhexyl)tetrahy-
drofuran-2-yl]octanoate (B). 1H NMR (300 MHz,
CDCl3): δ 3.94–3.76 (2H), 3.46–3.35 (2H), 3.65 (s,
6H, CO2CH3), 3.32 (s, 3H, OCH3), 3.28 (s, 3H, OCH3),
2.41 (t, J = 7 Hz, 4H, CH2CO2), 2.14–2.05 (m, 1H),
1.91–1.84 (m, 1H), 1.69–1.29 (20H), 0.87 (t, J = 6 Hz,
6H); 13C NMR (400 MHz, CDCl3): δ 174.54, 170.05,
166.60, 83.04, 82.40, 82.40, 82.24, 81.35, 80.42, 80.31,
74.24, 74.07, 74.01, 57.23, 56.84, 56.12, 51.67, 34.31,
34.05, 33.72, 33.62, 33.47, 32.18, 32.12, 29.97, 29.75,
29.43, 29.39, 29.34, 29.28, 29.00, 28.89, 26.41, 26.23,
26.05, 25.79, 25.14, 22.87, 22.78, 14.24; HRMS: (APCI)
m/z calculated for C20H38O5 359.2792, found 359.2787
(MH+).
31P-NMR experiments were performed on solutions
prepared by dissolving the derivatized MS samples (typi-
cally ~0.05 mmol) in 1 mL of CDCl3 in an NMR tube.
To this was added a known amount (0.02–0.05 mmol)
of phenol as an internal standard and excess amounts of
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J Am Oil Chem Soc
Methyl 10,12-dihydroxy-9,13-dimethoxyoctadecanoate
(C). 1H NMR (300 MHz, CDCl3): δ 4.02 (m, 1H), 3.86 (m,
1H), 3.76 (m, 1H), 3.64 (s, 3H, CO2CH3), 3.60 (m, 1H),
3.41 (s, 3H, OCH3), 3.40 (s, 3H, OCH3), 3.07 (br, 2H),
2.28 (t, J = 6 Hz, 2H, CH2CO2), 1.64–1.23 (20H) 0.85 (t,
J = 6 Hz, 3H); 13C NMR (400 MHz, CDCl3): δ 174.55,
84.49, 84.44, 74.04, 73.97, 58.29, 51.68, 38.86, 34.38,
32.29, 31.98, 29.82, 29.39, 29.36, 28.96, 26.35, 25.94,
25.13, 22.83, 14.26; HRMS: (APCI) m/z calculated for
C21H42O6 391.3054, found 391.3049 (MH+).
O
P
Cl
O
O
R
O
ROH
P
Et3N (5 equiv.)
CDCl3 (1 mL)
O
Scheme 3 Reaction of alcohols with chlorophospholane
O
O
O
Methyl
9-hydroxy-9-(4-hydroxy-5-pentyltetrahydro-
O
1
furan-2-yl)nonanoate (D). H NMR (300 MHz, CDCl3): δ
4.22 (br, 1H), 4.10 (m, 1H), 3.94 (m, 1H), 3.73 (m, 1H),
3.64 (s, 3H, CO2CH3), 3.45 (br, 1H), 3.35 (m, 1H), 2.28
(m, 2H), 2.01 (m, 1H), 1.81 (m, 1H), 1.65-1.21 (20H),
0.86 (t, J = 7 Hz, 3H); 13C NMR (400 MHz, CDCl3): δ
178.35, 178.34, 84.48, 80.44, 79.34, 74.23, 73.42, 71.65,
71.23, 51.70, 38.75, 38.06, 34.39, 34.27, 33.24, 32.25,
32.19, 32.09, 31.83, 31.72, 29.90, 29.70, 29.64, 29.43,
29.33, 29.26, 29.11, 28.90, 26.15, 25.57, 25.10, 24.86,
22.80, 14.26; HRMS: (APCI) m/z calculated for C19H36O5
345.2636, found 345.2632 (MH+).
E18:2
MeOH, 60 ºC, 4 h
OH
Amberlyst-15 (10%)
O
(B)
(4 isomers)
O
O
MeO
+
OMe
OMe
O
(C)
O
Methyl
10,12,15-trihydroxy-9,13,16-trimethoxyoc-
(4 isomers)
tadecanoate (E). 1H NMR (300 MHz, CDCl3): δ 3.80
(2H), 3.66 (s, 3H, CO2CH3), 3.43 (s, 6H, OCH3), 3.29
(s, 3H, OCH3), 3.02 (2H), 2.45 (2H), 2.30 (t, J = 6 Hz,
2H, CH2CO2) 1.70–1.26 (16H), 0.89 (t, J = 6 Hz, 3H);
13C NMR (400 MHz, CDCl3): δ 174.88, 81.33, 81.03,
80.99, 76.72, 75.01, 74.64, 57.25, 57.06, 56.14, 56.12,
51.68, 33.81, 32.15, 30.85, 30.28, 30.22, 29.45, 29.33,
27.42, 26.54, 26.25, 25.16, 22.80, 14.27; HRMS: (APCI)
m/z calculated for C22H44O8 437.3109, found 437.3100
(MH+).
OH OH
+
HO
(D)
(2 isomers)
O
O
OH
O
Scheme 4 Reaction of E18:2 with methanol
31.75, 31.51, 30.38, 30.05, 30.01, 29.97, 29.42, 29.11,
26.44, 26.01, 25.14, 25.08, 24.86, 22.84, 14.81; HRMS:
(APCI) m/z calculated for C20H38O7 391.2690, found
391.2670 (MH+).
Methyl
8-[3-hydroxy-5-(3-hydroxy-1,4-dimethox-
yhexyl)tetrahydrofuran-2-yl]octanoate (F). 1H NMR
(300 MHz, CDCl3): δ 4.24 (m, 1H), 4.04 (m, 1H), 3.88
(m, 1H), 3.78 (m, 1H), 3.66 (s, 3H, CO2CH3), 3.43 (s, 3H,
OCH3), 3.33 (s, 3H, OCH3), 3.29 (m, 1H), 2.43 (m, 1H),
2.30 (t, J = 6 Hz, 2H, CH2CO2), 1.86–1.16 (16H), 0.88 (t,
J = 6 Hz, 3H); 13C NMR (400 MHz, CDCl3): δ 172.97,
86.45, 81.03, 81.50, 74.11, 74.05, 71.78, 58.34, 57.01,
56.13, 52.62, 51.68, 34.55, 34.31, 32.57, 32.27, 30.60,
29.88, 29.74, 29.64, 29.41, 29.34, 29.29, 27.28, 26.99,
26.82, 26.49, 26.24, 25.91, 25.72, 25.28, 22.85, 14.28;
HRMS: (APCI) m/z calculated for C21H40O7 405.2847,
found 405.2844 (MH+).
31P‑NMR Data for the Phospholane‑Derivatized
Products (Structures of Compounds are given in
Schemes 2, 3, 4, and 5)
E18:1(MeOH) (A). 31P NMR (600 MHz, CDCl3): δ 146.88,
146.87.
E18:2(MeOH). 31P NMR (600 MHz, CDCl3): δ 148.47,
147.89, 147.75, 147.69, 147.60, 147.57, 147.54, 147.52,
147.48, 147.45, 147.38, 147.12, 147.09, 146.99, 146.94,
146.83, 146.81, 146.76.
Methyl 8-[5-(1,3-dihydroxy-4-methoxyhexyl)-3-hydrox-
ytetrahydrofuran-2-yl]octanoate (G). H NMR (300 MHz,
1
CDCl3): δ 3.66 (s, 3H, CO2CH3), 3.61 (2H) 3.32 (s, 3H,
OCH3), 3.28 (m, 1H), 3.14 (m, 1H), 3.05 (2H), 2.29
(t, J = 6 Hz, 2H, CH2CO2), 1.66–1.24 (16H), 0.92 (t,
J = 6 Hz, 3H); 13C NMR (400 MHz, CDCl3): δ 186.98,
87.10, 84.20, 83.11, 82.28, 51.68, 34.37, 34.29, 32.15,
Compound B. 31P NMR (600 MHz, CDCl3): δ 147.49,
147.45, 146.82, 146.75.
Compound C. 31P NMR (600 MHz, CDCl3): δ 147.81,
147.75, 147.67, 147.63, 147.51, 147.43, 146.90, 146.88.
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J Am Oil Chem Soc
O
achieves this transformation in lower yields (~90 vs 99 %
for mCPBA), but the latter requires stoichiometric amounts
of an expensive reagent and is therefore not economical
on a large scale. Therefore, in small-scale reactions (i.e.,
1.0 mL of alkene), the mCPBA method was preferred,
while the hydrogen peroxide approach was used in scaled-
up reactions.
O
O
O
O
E18:3
Amberlyst-15 (10%)
MeOH, 60 ºC, 4 h
OH OMe
OMe
O
A typical fatty acid composition of soybean oil is
51 % linoleate (18:2), 25 % oleate (18:1), 9 % linolenate
(18:3), 12 % palmitate (16:0), and 3 % stearate (18:0). In
the epoxidation of MS to EMS, the double bonds in 18:1,
18:2, and 18:3 are epoxidized while the saturated FAME
(16:0 and 18:0) do not react. In order to analyze the com-
position of the EMS, it was useful to examine the products
obtained from the epoxidation of the individual compo-
nents of methyl soyate. Both E18:1 and E18:2, which had
been previously reported [21], were prepared from 18:1
and 18:2 using mCPBA as the oxidant. Although not pre-
viously reported, we also prepared the tri-epoxide E18:3
using mCPBA.
O
OMe
OH OH
(E)
(6 isomers)
+
OMe
OH
O
HO
O
O
MeO
(F)
(12 isomers)
+
Another method for the production of EMS involves the
transesterification of epoxidized soybean oil (ESO) with
methanol using sodium methoxide as the catalyst [11].
ESO was previously prepared by the complete epoxidation
of soybean oil [22]; it is commercially available and is rela-
tively inexpensive. The reaction of ESO with methanol in
the presence of sodium methoxide gave EMS in quantita-
tive yield. This was demonstrated by the disappearance of
the triglyceride proton signals and the appearance of the
OMe
OH
O
HO
O
O
HO
(G)
(8 isomers)
Scheme 5 Reaction of E18:3 with methanol
1
methyl ester group in the H-NMR spectrum of EMS. The
NMR spectrum also showed that the epoxide group is sta-
ble under the transesterification conditions.
Compound D. 31P NMR (600 MHz, CDCl3): δ 147.54,
147.49, 147.01, 146.95.
E18:3(MeOH). 31P NMR (600 MHz, CDCl3): δ 148.13,
148.08, 147.92, 147.90, 147.71, 147.69, 147.66, 147.61,
147.53, 147.47, 147.42, 147.40, 147.38, 147.35, 147.33,
147.31, 147.22, 147.18, 147.14, 147.10, 147.06, 147.04,
147.02, 146.99, 146.97, 146.94, 146.91, 146.86, 146.82,
146.77, 146.72, 146.68, 146.63, 146.59, 145.96, 145.91,
145.58, 145.48.
Reactions of Epoxides with Alcohols
Reaction of E18:1 with Methanol to Give E18:1(MeOH)
Using conditions similar to those reported previously [23,
24], we reacted E18:1 with methanol in the presence of
Amberlyst-15 catalyst (which contains –SO3H Brønsted
acid groups) to produce E18:1(MeOH). This reaction gives
two regioisomers (A) depending on the mode of alcohol
addition to the epoxide group (Scheme 2). Analysis of this
regioisomeric mixture by LC-APCI showed two peaks in
the chromatogram with 5.3 and 5.6 min retention times, and
both displayed molecular ion peaks of 345 (MH+) for A.
Although the peaks are not completely separated, their inte-
EMS(MeOH). 31P NMR (600 MHz, CDCl3): δ 148.47,
147.89, 147.75, 147.69, 147.60, 147.57, 147.54, 147.52,
147.48, 147.45, 147.38, 147.12, 147.09, 146.99, 146.94,
146.88, 146.87, 146.83, 146.81, 146.76.
Results and Discussion
1
grations are in an approximately 1:1 ratio. In the H-NMR
Epoxidation of Methyl Soyate
spectrum of E18:1(MeOH), the ester methyl (3.65 ppm)
and the ether methyl (3.40 ppm) signals integrate in a 1:1
ratio, which is consistent with the presence of equal num-
bers of ester and ether methyl groups, as is expected for the
isomeric compounds with structures A.
Two common methods for the epoxidation of olefins
employ either hydrogen peroxide and formic acid [17–20]
or meta-chloroperbenzoic acid (mCPBA) [21]. The former
1 3

J Am Oil Chem Soc
An alternate method of characterizing these new com-
pounds involves the use of a chlorophospholane reagent
[14], which reacts with alcohol groups in organic com-
pounds (Scheme 3). This method has been used for the
detection and quantitation of phenolic groups in coal liq-
uids [25, 26], as well as for the quantitation of mono- and
diglycerides in olive oil [15, 16]. The 31P-chemical shift is
very sensitive to its chemical environment, which allows
for the quantitation of –OH groups in molecules with
very similar chemical environments as in the A isomers of
E18:1. Treatment of E18:1(MeOH) with chlorophospho-
lane and analysis by 31P showed two peaks at 146.88 and
146.87 that integrate in a 1:1 ratio. This result is additional
evidence that E18:1(MeOH) consists of the two A regioiso-
mers proposed in Scheme 2.
The peaks at 2.2 and 2.5 min in the LC chromatogram
both show MH+ molecular ion peaks for compound B in
Scheme 4. This product is presumably formed as a result of
MeOH addition to one of the epoxides. The epoxide oxy-
gen in the resulting intermediate then adds to a carbon of
the second epoxide to give the cyclic 5-membered ether
ring. Depending on the initial site of attack of the methanol
on the E18:2 epoxides, the formation of four isomers of B
is possible. (This mechanism is drawn in detail in the sup-
porting information). Cyclic ethers of this type have been
reported from the reaction of E18:2 with water under acidic
conditions where the presence of the cyclic ether group
in these products was indicated by LC–MS fragmentation
analysis as well as by NOE NMR spectroscopy [29, 30].
The proposed structure B is based on the molecular ion
fragment in the APCI spectrum, which gives the molecu-
lar formula corresponding to B. This structure is further
High oleic soybean oil (HOSO) was transesterified by
reaction with methanol in the presence of sodium methox-
ide catalyst to give HO18:1. Analysis of the 1H-NMR spec-
trum [27, 28] of HO18:1 showed that it consisted primar-
ily (86 %) of 18:1. After HO18:1 was epoxidized and then
reacted with methanol, the product EHO18:1(MeOH) was
1
corroborated by the H-NMR spectrum which shows that
the methyl ester (3.65 ppm) and methyl ether (3.32 and
3.28 ppm) groups integrate in a 1:1 ratio, showing that for
each ester methyl there is one ether methyl group.
1
isolated. Its H, 13C, and 31P-NMR spectra were the same
The peaks at 1.4 and 1.8 min both have molecular ion
peaks (MH+ = 345) in their mass spectra that correspond
to the cyclic hydrolysis product D in Scheme 4. The two
peaks indicate that this compound exists as two regioi-
somers, presumably differing by the initial site of water
attack on the epoxide groups to form the dihydroxy tet-
rahydrofuran products D. The retention times of D in
E18:2(MeOH) correspond exactly to the retention times of
the pure D prepared from E18:2 according to Ref. [30]. The
formation of hydrolysis compound D indicates that water is
formed during the reaction of E18:2 with methanol in the
presence of the acidic Amberlyst-15. The origin oand other
alcohols) in the presence off this water is not obvious, but a
possibility is that dehydration of methanol to give dimethyl
ether and water occurs; such an Amberlyst-15-catalyzed
dehydration of alcohols has been reported previously [31].
The 31P-NMR spectrum of the product of the reaction
of E18:2(MeOH) with the chlorophospholane derivat-
izing agent showed 16 distinct phosphorus signals in the
146–148 ppm region. A sample of pure compound B dis-
played four 31P-NMR peaks, indicating the presence of 4
–OH groups, suggesting that this component is a mixture
of 4 regioisomers, each of which has a single –OH group.
Compound C features 8 peaks in its 31P-NMR spectrum,
indicating the presence of 8 hydroxy groups, which is con-
sistent with its proposed structure. The four possible regioi-
somers of this structure would each possess two hydroxy
groups. Finally, the phosphorylated product D exhibits four
distinct 31P-signals, which is consistent with the presence
of two regioisomers, each of which possesses two differ-
ent hydroxy groups. Thus, the sixteen 31P-NMR peaks
observed in the spectrum of E18:2(MeOH) is consistent
as those of E18:1(MeOH).
Reaction of E18:2 with Methanol to Give E18:2(MeOH)
The di-epoxide E18:2 reacts with methanol, under the same
conditions as for the reaction of E18:1 (Scheme 2), to form
a mixture of compounds we designate as E18:2(MeOH)
(Scheme 4). To our knowledge, this reaction has not been
reported in the literature. Analysis of the products by LC-
APCI showed five distinct peaks in the LC chromatogram
at 1.4, 1.7, 1.8, 2.2, and 2.5 min.
Flash
silica-gel
column
chromatography
of
E18:2(MeOH) yielded fractions that contained pure B, C,
and D. Integration of the methyl ester group in each frac-
tion against a Ph3CH standard yielded the molar percentage
composition of each of these compounds in E18:2(MeOH)
which is 53 % B, 26 % C, and 21 % D. The cyclic metha-
nolysis product B is clearly the major product of the acid-
catalyzed reaction of E18:2 with methanol.
The peak in the LC chromatogram at 1.7 min has a
molecular ion peak (MH+ = 391) that corresponds to the
proposed structure of C in Scheme 4. This compound repre-
sents the product resulting from methanol addition to both
of the epoxide rings to give a product containing two –OH
and two –OMe groups. Depending on the site of attack of
the alcohol on the epoxides, there are four possible regioi-
1
somers of this compound. An H-NMR spectrum of pure
compound C shows peaks for the ester methyl (3.64 ppm)
and the ether methyl groups (3.40, 3.41 ppm) that integrate
in a 1:2 ratio, which is consistent with two ether methyl
groups for each ester methyl group in structure C.
1 3

J Am Oil Chem Soc
with the number of peaks expected for a mixture of B, C,
and D.
The 31P-NMR spectrum of the mixture resulting from
the reaction of E18:3(MeOH) with the chlorophospholane
reagent showed 38 peaks in the 145–148 ppm region. The
large number of peaks may be attributed to the large num-
ber of alcohol-containing products, including regioisomers,
in E18:3(MeOH). In addition, many of the peaks are poorly
resolved, thus making it difficult to make assignments of
the molecular species in E18:3(MeOH).
Reaction of E18:3 with Methanol to Give E18:3(MeOH)
The tri-epoxide E18:3 was reacted with methanol in the
presence of Amberlyst-15 under the same conditions as
described above for E18:1 and E18:2. To the best of our
knowledge, this reaction has not been reported previously.
Analysis of the product by LC-APCI showed three dis-
tinct peaks with molecular ion formulas that correspond
to compounds E (MH+ = 437, 1.0 min), F (MH+ = 405,
1.2 min), and G (MH+ = 391, 0.9 min) (Scheme 5). The
E18:3(MeOH) mixture was also separated by flash silica
gel chromatography, and the amounts of compound in each
fraction were quantified by integration of the ester methyl
peaks in the 1H-NMR spectra of the compounds. The com-
position was found to be 10 % E, 51 % F, and 39 % G.
Thus, the major component in E18:3(MeOH) is the cyclic
methanolysis compound F.
Reaction of EMS with Methanol
Considering the complex mixture of compounds in EMS,
the product resulting from its reaction with methanol is
expected to be even more complex. There are two potential
methods of producing EMS(MeOH) using ESO as the start-
ing material. The first involves the base-catalyzed transes-
terification of ESO to EMS, followed by an acid-catalyzed
reaction of the epoxide groups in EMS with methanol to
give EMS(MeOH) (Route 1 in Scheme 6). The second
route involves the acid-catalyzed reaction of the epoxide
groups in ESO with methanol to form ESO(MeOH) as an
intermediate, which is then transesterified with methanol
in a base-catalyzed reaction to give EMS(MeOH) (Route 2
in Scheme 6). The primary advantage of Route 2 is that it
involves fewer mechanical steps. Route 1 requires removal
of the methanol solvent by evaporation after the transesteri-
fication step in order to separate the glycerol side product
and NaOMe catalyst; then methanol must be re-added to
the EMS in the second step to give EMS(MeOH). Route
2, on the other hand, utilizes the same methanol solvent for
both steps of the process, because the Amberlyst-15 cata-
lyst can be removed simply by filtration. Then the NaOMe
catalyst can be added to the reaction solution for the second
step.
The molecular ion for compound E corresponds to the
acyclic compound that results from MeOH addition to each
1
of the three epoxides in E18:3. The H-NMR spectrum
yields an ester methyl/ether methyl integration ratio of 1:3,
which is consistent with the proposed structure of E. The
molecular ion peak suggests that compound F contains a
cyclic tetrahydrofuran ether compound similar to that in B.
Presumably this ring forms as the result of MeOH addition
to one of the epoxides, followed by intramolecular cycli-
zation with a second epoxide to give the cyclic ether. The
third epoxide ring is simply opened upon reaction with
1
methanol to give F. Integration of the H-NMR spectrum
of F yields a 1:2 ester methyl/ether methyl ratio, which is
consistent with the proposed structure for F.
Compound G results from the addition of water to one
epoxide followed by cyclization to give the cyclic ether
group; reaction of the remaining epoxide with methanol
Both of the aforementioned routes to EMS(MeOH)
were investigated. Route 1 yielded quantitative conversion
of ESO to EMS in the first step, followed by a 95 % yield
for the conversion of EMS to EMS(MeOH) in the second
step. In contrast, the first step of Route 2 gave a gummy
substance that coated the Amberlyst-15 catalyst during
the reaction. This compound, which is presumed to be
1
gives the final product G. The H-NMR spectrum of this
compound provides an ester methyl/ether methyl integra-
tion of 1:1, which is consistent with the structure proposed
for G.
Scheme 6 Routes for the con-
version of ESO to EMS(MeOH)
NaOMe(1% w/w)
Amberlyst-15 (10%)
MeOH, 60ºC, 4 h
95%
MeOH, 60ºC, 1 h, >99%
-glycerol
EMS(MeOH)
EMS(MeOH)
ESO
ESO
EMS
Route 1
Amberlyst-15 (10%)
MeOH
NaOMe(1% w/w)
MeOH, 60ºC, 1 h
97% (2-steps)
-glycerol
ESO(MeOH)
60ºC, 4 h
Route 2
1 3

J Am Oil Chem Soc
Table 1 LC-APCI data for
EMS(MeOH)
Fraction Retention time (min) MH+
Formula
Percentage comp. (%)a Proposed structure
1
2
0.900
1.017
1.167
1.385
1.663
1.811
2.187
2.548
5.317
5.645
391.2670 C20H38O7
405.2844 C21H40O7
437.3100 C22H44O8
345.2632 C19H36O5
0.4
0.1
1.5
8
G
E
F
3
4
D
C
D
B
B
A
A
5
391.3049 C21H42O6 14
345.2633 C19H36O5 10
359.2787 C20H38O5 13
359.2785 C20H38O5 22
345.2993 C20H40O4 13
345.2993 C20H40O4 19
Compound labels are indicated
in bold
6
7
a
Percentage compositions are
based on 1H-NMR integrations
of ester methyl peaks in spectra
of each of the fractions against a
Ph3CH standard
8
9
10
polymerized ESO, also reduced the activity of the catalyst.
Moreover, recycling of the catalyst in Route 2 was not fea-
sible, as the separation of the catalyst from the gummy pol-
ymer proved to be unsuccessful. This gummy material does
not form when using Route 1. Therefore, although Route
2 involves fewer mechanical steps, Route 1 was more effi-
cient and was used for the synthesis of EMS(MeOH) for all
subsequent studies.
It should be noted that the reaction of ESO with MeOH
(and other alcohols) in the presence of H2SO4 catalyst at
80–100 °C was previously reported [32]. Under these con-
ditions, complete epoxide ring opening occurred but only
partial transesterification. No tetrahydrofuran-type struc-
tures, such as B or F, were identified among the compo-
nents of those products.
tert-butanol gave low yields of the expected epoxide ring-
opened products.
The 31P-NMR spectrum of EMS(MeOH) functionalized
with the chlorophospholane revealed peaks for the com-
pounds present in both E18:1(MeOH) and E18:2(MeOH)
with the same chemical shifts as those observed in the pure
samples as discussed earlier. Integrations of these peaks
showed that the E18:1(MeOH) and E18:2(MeOH) com-
pounds are present in a 1:2.54 ratio. On the basis of the
31P-NMR spectrum, 72 % of the alcohol (–OH) groups in
EMS(MeOH) are derived from reactions of E18:2, while
28 % are derived from reactions of E18:1. Interestingly,
no 31P-NMR peaks for phosphorylated E18:3(MeOH)
were detected in phosphorylated EMS(MeOH), which
may be due to the relatively small amount of E18:3 in
EMS(compared with E18:2 and E18:1) and to the large
number of different alcoholic groups in E18:3(MeOH), as
observed in 31P-NMR spectra of phosphorylated products
of E18:3(MeOH) (see above).
The product, EMS(MeOH), of the Route 1 reaction was
analyzed by LC-APCI (Table 1). The retention times and
molecular ions observed are identical to those obtained
from products of the reactions of E18:1, E18:2, and E18:3
with methanol, discussed above. The EMS(MeOH) was
separated into 10 fractions by flash chromatography on a
silica column. The percentage molar compositions of the
Reaction of EMS with Carbon Dioxide to Form EMS(CO2)
1
individual fractions are based on H-NMR integrations of
Epoxidized methyl soyate (EMS) was previously reacted
with carbon dioxide using tetra(n-butyl)ammonium bro-
mide (TBAB) as the catalyst [12]. The product of this
reaction was characterized by IR spectroscopy, which
established the presence of carbonate groups. After we pre-
pared EMS(CO2) by this method, the resulting product was
separated by flash silica gel chromatography to give pure
fractions of compounds H and I (Scheme 7). These com-
pounds were characterized by LC-APCI, which exhibited
MH+ ion peaks at 415 and 357, respectively. Analysis of
the ester methyl peaks relative to the Ph3CH standard. The
products, E, F, and G, derived from E18:3, make up only
a small percentage (~2 %) of the functionalized products
in EMS(MeOH) (Table 1). The E18:1(MeOH) compounds
A make up 31 % of the mixture which is consistent with
the fact that 18:1 makes up ~30 % of the unsaturated com-
pounds in methyl soyate. The family of E18:2(MeOH)
compounds, B, C, and D, derived from E18:2, make
up the largest percentage (67 %) of the functionalized
EMS(MeOH).
1
the pure fractions by H-NMR spectroscopy revealed that
Ethanol, n-propanol, n-butanol, and 2-methoxyethanol
were also reacted with EMS in the presence of Amber-
lyst-15 under conditions similar to those used with meth-
anol to give other solvents EMS(ROH). More sterically
hindered alcohols such as iso-propanol, sec-butanol, and
EMS(CO2) contained 63 % H and 37 % I. None of com-
pound J was found after column purification. The only
product of the carboxylation of E18:2 is H and similarly,
the only products of the reactions of E18:1 and E18:3 with
CO2 are I and J, respectively. None of the epoxide remains
1 3

J Am Oil Chem Soc
Scheme 7 Carboxylation of
EMS to EMS(CO2)
O
O
O
O
O
O O
O
(H)
+
O
O
O
O
O
TBAB (10%)
CO2 (150 PSI)
120 ºC, 16 h
(I)
EMS
+
O
O
O
O
O
O
O O
O O
O
(J)
+
saturated FAMEs
EMS(CO2)
after these reactions, as evidenced by the complete loss of
epoxide peaks in the 1H-NMR spectra.
a larger KB value indicates a more effective solvent.
Recently, Knöthe and Steidley [33] reported a modified
Kauri-butanol procedure that used only 5 g of Kauri-
butanol solution instead of the 20 g used in the standard
method [35]; they found the same KB values as those
determined with 20 g. We have found that the amount of
Kauri-butanol solution used for these titrations can be
decreased further to 1.00 g while still giving the same
or nearly the same KB values as those obtained with 5
and 20 g. For example, we obtained the same KB value
(30) for hexanes using 1.00 or 5.00 g of Kauri-butanol
solution. For p-xylene, the KB value on a 5.00 g scale
was determined to be 97, while on a 1.00 g scale, it was
101. The use of 1.00 g of the Kauri-butanol solution
required a modification of the KB Eq. 1. Here, X is the
amount (1.00 g) of the KB solution used, C is the vol-
ume (mL) of
Reaction of EMS with Acetone to Form EMS(Me2CO)
The acetonide of EMS was prepared according to a litera-
ture procedure [13], which involves treatment of EMS in
the presence of a Lewis acid (FeCl3) using acetone as the
solvent as well as reactant (Scheme 8). The product is a
mixture of acetonides, K, L, and M, as evidenced by the
presence of the MH+ molecular ions in an LC-APCI analy-
sis of the crude product EMS(Me2CO). The previous litera-
ture report [13] characterized the product by its 13C-NMR
spectrum, which contained a peak at 107 ppm indicative
of quaternary carbons; this peak was also observed in our
studies.
ꢀ
ꢁ
ꢂ
Physical Properties of the Solvents
KB = (65)[(20C/X) − B] (A − B) + 40
(1)
Kauri‑Butanol (KB) Values
tested solvent required to reach the endpoint, A is the vol-
ume of toluene (mL) required to titrate 20 g of KB solu-
tion as provided by the KB solution supplier, and B is the
volume (mL) of a toluene-heptane blend required to titrate
20 g of KB solution as provided by the KB solution sup-
plier. For the particular KB solution that was used in our
titrations, A = 104.8 and B = 38.2. Therefore, for our
determinations that utilized 1.00 g of KB solution, the KB
equation is shown below.
One of the standard methods of characterizing the solu-
tion properties of solvents is the determination of their
Kauri-butanol values [33, 34]. This method involves
the titration of a standard solution of Kauri gum in
n-butanol with the solvent of interest until the solution
reaches a cloud point. The amount of solvent titrant
required is used to calculate the KB value. In general,
1 3

J Am Oil Chem Soc
Scheme 8 Reaction of
EMS with acetone to give
EMS(Me2CO)
O
O
O
O
O
O
(K)
+
O
O
O
O
FeCl3 (0.1 mol%)
acetone
(L)
EMS
+
rt, 24 h.
O
O
O
O
O O
O
O
(M)
+
saturated FAMEs
EMS(Me2CO)
ꢀ
ꢁ
ꢂ
Table 2 KB Values of prepared solvents using 1.00 g of Kauri-
butanol solution
KB = (65)(20C−B) (A−B) + 40
(2)
The KB values of the solvents prepared in the present
study are shown in Table 2. It is clear that each of these
solvents has a considerably higher KB value than that of
methyl soyate (57, Table 2, Entry 1); note that our meas-
ured KB value is very similar to that (58) reported pre-
viously [5, 6], although a higher value of 82.7 has also
been reported for methyl soyate [34]. Of the solvents pre-
pared in the present investigation, the KB value is lowest
for EMS(Me2CO) (280, Entry 3). EMS(which possesses
epoxide functional groups) has a KB value of 249 (Entry
2). By contrast, all of the prepared solvents reported
herein have higher KB than those in Entries 1 and 2. It
is interesting that the KB value (610) for EHO(MeOH),
derived from high oleic soybean oil, is much higher than
the KB value (369) for EMS(MeOH) derived from stand-
ard soybean oil. The major component in EHO(MeOH)
has structure A, which is the product of the methanolysis
of E18:1 (Scheme 2); this structure is presumably at least
partially responsible for its higher KB value as compared
with that of EMS(MeOH) in which the major structure is
the cyclic tetrahydrofuran derivative B formed in the reac-
tion of E18:2 with methanol (Scheme 4). It appears to be
the combination of the polar groups and the hydrocarbon
chain that gives these solvents such unprecedentedly high
KB values.
Entry Solvent
Amt. solvent used (mL) KB value
1
2
3
4
5
6
7
8
Methyl soyate
2.8
12.6
14.2
18.6
28.2
31.1
57
249
280
366
553
610
725
852
EMS
EMS(Me2CO)
EMS(MeOH)
EMS(CO2)
EHO(MeOH)
EMS(HOCH2CH2OCH3) 37.0
EMS(EtOH) 43.5
Melting Points and Initial Boiling Points
The procedure for determining the melting points reported
in Table 3 involved first freezing the solvent (~10 mL) in
a dry ice/acetone bath and allowing the solvent to slowly
warm to room temperature, noting the temperature,
MP(start), at which the solvent first began to show liquid
and then the temperature, MP(end), at which the solid was
completely melted. All the boiling points in Table 3 were
performed at 1 Torr pressure because of their high boiling
points at atmospheric pressure. The initial boiling points
listed in Table 3 are temperatures of the solvents at which
they first began to bubble.
1 3

J Am Oil Chem Soc
Table 3 Physical properties of prepared solvents
Entry Solvent Initial BP (1 Torr) °C MP (start) (°C) MP (end) (°C) Karl Fischer water sol. (%) Viscosity at 25.0 °C (cSt)
1
2
3
4
5
Methyl soyate
51.5
68.8
72.8
−49.1
−33.0
−33.4
−39.0
−23.9
1.0
6.5
4.6
2.2
9.3
0.05 [36]
0.539
3.9–4.3 [3, 4, 37]
69.67
EMS(MeOH)
EMS(EtOH)
0.522
59.42
EMS(HOCH2CH2OCH3) 55.0
EMS(CO2) 53.1
0.487
38.69
0.242
178.4
When compared to the melting point of methyl soyate,
Summary and Conclusions
all of the prepared solvents have higher melting points.
Likewise, they all have higher initial boiling points than
methyl soyate. All of them would therefore have higher
normal boiling points than methyl soyate, which has a nor-
mal boiling point of 216 °C [3, 4]. The vapor pressures of
EMS(MeOH), EMS(EtOH), EMS(HOCH2CH2OCH3), and
EMS(CO2) were measured with a mercury manometer. In
every case, the vapor pressure was very low (<1 mmHg at
19 °C).
The goal of this project was to convert methyl soyate (bio-
diesel derived from soybean oil) into a solvent that pos-
sesses properties that would make it capable of dissolving a
broad range of polar and non-polar substances. One meas-
ure of the solubilizing properties of a solvent is its Kauri-
butanol value. All of the solvents described in this paper,
EMS(MeOH), EMS(EtOH), EMS(HOCH2CH2OCH3),
EMS(CO2), and EMS(Me2CO), have substantially higher
KB values (280–852) than that (57) of methyl soyate
(MS). Because of the low cost of MeOH and potential low
cost of EMS(MeOH), we characterized EMS(MeOH) in
the greatest detail and found that it consisted of molecu-
lar components that contained –OH and –OMe functional
groups near the center of the C18 hydrocarbon chains. The
major component (B in Scheme 4) also contained a cyclic
tetrahydrofuran unit derived from methyl linoleate (18:2).
It is presumably these polar groups that give EMS(MeOH)
its high KB value (366). The higher concentration of A in
EHO(MeOH), derived from high-oleic soybean oil, reason-
ably accounts for the even higher KB value (610) of this
solvent.
Solubility of Water in the Solvents
Karl Fischer titration reveals that water is extremely insolu-
ble in methyl soyate (0.05 % water) [36]. All of our sol-
vents, however, dissolve more water than methyl soyate
(Table 3) especially those derived from reactions of EMS
with alcohols (ca. 0.5 %). The solvent without –OH groups,
EMS(CO2) has a lower water solubility of 0.24 %, pre-
sumably because of its reduced ability to participate in
hydrogen-bonding.
A wide range of organic solvents are readily soluble in
EMS(MeOH). These include methanol, ethanol, acetoni-
trile, diethyl ether, toluene, and hexane.
The excellent solvent properties of EMS(MeOH) are
also reflected in its ability to dissolve solvents ranging from
hydrogen-bonding, polar solvents such as methanol to non-
polar solvents such as hexane. The versatile solubilizing
properties of EMS(MeOH) and our other solvents, together
with their low volatilities (VOC), will hopefully make them
useful in a variety of solvent and surfactant applications.
Viscosities of the Solvents
Kinematic viscosities of the solvents were also deter-
mined (Table 3). Methyl soyate is reported to have a
viscosity of ~4 cSt [3, 4, 37], whereas our functional-
ized solvents possess viscosities ranging from 39 cSt
for EMS(HOCH2CH2OCH3) to 178 cSt for EMS(CO2),
which are all much higher than that of methyl soyate.
Presumably the added polar –OH and –OR groups are
largely responsible for the high viscosities of the alcohol-
derived solvents EMS(ROH), as has been reported [38,
39] for the methyl ester of ricinoleic acid, with a viscos-
ity of 15.4 cSt at 40 °C. The unusually high viscosity
of EMS(CO2) is consistent with the previously-reported
high viscosities of carbonated soybean and vernonia oils
[40].
Acknowledgments The authors thank the United Soybean Board
for support. ESO was kindly provided by Arkema and ChemCeed.
HOSO was kindly supplied by Stratas Foods.
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