ionic liquid. A spatula tip of betaine was usually added to a
UV-cuvette containing the ionic liquid and after homogeniza-
m, CHOCH2), 4.17 (1 H, dd, J6b,5 = 12.0, 6.2, CH2OCO), 4.37
(1 H, dd, J6a,5 = 12.0, 2.2 Hz, CH2OCO), 4.64 (1 H, d, J1,2
=
◦
tion the UV-lmax/50 C was detected. An ET (ionic liquid) value was
3.6 Hz, CHOCH3), 4.86 (3 H, s, 3¥OH).
calculated (ET = h·C·nmax·Na) and transformed into an ENT value
dC(100 MHz, CD3OD) 14.6 (p), 23.9 (s), 26.2 (s), 30.6 (4 ¥
s), 33.2 (s), 35.2 (s), 55.7 (p), 64.9 (p), 71.2(s), 72.1(s), 73.6(t),
75.2(s), 101.4(t), 175.5(q).
by ENT = {ET (ionic liquid)-30.7}/32.4.
Microscopy of ionic liquid coated lipase carriers
FT-IR (KBr): 3379 b-w, 2918 w-m, 2850 w-m, 1728 s, 1464
m-s, 1417 m.
Optical microscopy: a Zeiss AxioPlan with Objectif EC Plan-
Neofluar with 25¥ magnification and an Olympus Europe
Highlight 3000 lamp as light source were used. Data was
analysed with AnalySIS [Soft Imaging System].
m/z (APCI-MS) 349.2 (M-H+, C17H32O7 requires 348.4404).
Melting point (DSC): 51.40 ◦C.
6-O-dodecanoyl-methyl-a-D-glucopyranoside 3b
Scanning electron microscopy (SEM): a Zeiss type LEO 1525
FEM equipped with a GEMINI column and an "In-Lens"
detector served in the submicron analysis; for elemental analysis
an EDX-Link-ISIS Pentafet Super ATW detector was used.
The samples were immobilized on a carbon patch fixed on an
aluminium support and pretreated with gold plasma.
dH(400 MHz; d6-DMSO) 0.84 (3 H, t, J12¢,11¢= 6.9 Hz, CH2CH3),
1.23 (16 H, m, 8¥CH2), 1.50 (2 H, m, CH2CH2CH2), 2.27 (2 H,
t, J2¢,3¢ = 7.3, CH2CO), 3.04 (1 H, m, CHOH), 3.18 (1 H, m,
CHOH), 3.24 (3 H, s, OCH3), 3.36 (1 H, m, CHOH), 3.50 (1 H,
m, CHOCH2), 4.00 (1 H, dd, J6b,5 = 11.7, 6.8 Hz, CH2OCO),
4.28 (1 H, dd, J6a,5 = 12.0, 2.0 Hz, CH2OCO), 4.51 (1 H, d, J1,2
=
3.7 Hz, CHOCH3), 4.76 (1 H, d, JOH,2 = 6.4 Hz, OH), 4.85 (1 H,
d, JOH,3 = 4.9 Hz, OH), 5.10 (1 H, d, JOH,4 = 5.9 Hz, OH).
dC(100 MHz; CD3OD) 13.1(p), 22.4(s), 24.7(s), 6¥29.0(s),
31.7(s), 33.6(s), 54.2(p), 63.4(p), 69.7(s), 70.5(s), 72.1(t), 73.6(s),
99.9(t), 174.0(q).
FT-IR (KBr): 3379 b-w, 2915 w-m, 2849 w-m, 1727 s, 1474
m-s, 1464 m.
m/z (APCI-MS) 377.2 (M-H+, C19H36O7 requires 376.4946).
Melting point (DSC): 70.30 ◦C.
General procedures for
6-O-alkanoyl-methyl-a/b-D-glucopyranosides 3a–e
Method A: Transformation in organic solvent. Typically, the
reaction mixture consisted of equimolar amounts of methyl-a-
D-glucopyranoside 1 (0.97 g, 5 mmol) and (5 mmol) fatty acid
R
2a–e catalysed by Novozymꢀ 435 (0.49 g, 50% w/w of sugar)
dissolved in an organic solvent (10 ml). Thermally activated
˚
molecular sieves (800 mg, 3A, 10 mesh) were used for the
adsorption of condensing water. The reaction mixture was
placed in a 20 ml sealed glass vial, and incubated for 1–3 days in
a Shel lab 1004 hybridization oven (Sheldon MFG. Inc., United
States) at 60–80 ◦C and a rotational speed of 7 rpm. Conversions
were determined by HPLC according to the method described
above. In order to obtain purified products 3a–e dried reaction
mixtures were dissolved in ethylacetate and eluted on a silica gel
6-O-tetradecanoyl-methyl-a-D-glucopyranoside 3c
dH(400 MHz, CD3OD) 0.90 (3 H, t, J14¢,13¢ = 6.8 Hz, CH2CH3),
1.29 (20 H, m, 10¥CH2), 1.62 (2 H, m, CH2CH2CH2), 2.34 (2
H, t, J2¢,3¢ = 7.6 Hz, CH2CO), 3.27 (1 H, m, CHOH), 3.37 (1 H,
m, CHOH), 3.39 (3 H, s, OCH3), 3.60 (1 H, m, CHOH), 3.68 (1
H, m, CHOCH2), 4.18 (1 H, dd, J6b,5 =11.6, 6.2 Hz, CH2OCO),
˚
(60A) column by ethylacetate.
4.37 (1 H, dd, J6a,5 = 12.0, 2.2 Hz CH2OCO), 4.64 (1 H, d, J1,2
4.0 Hz, CHOCH3), 4.86 (3 H, s, 3¥OH).
=
Method B: Solvent free conditions. The fatty acids were
heated above the melting point (60–70 ◦C) in order to function
as substrate solvent. The other parameters correspond to
Method A.
dC(100 MHz; CD3OD) 14.6(p), 23.9(s); 26.2(s), 8 ¥ 30.9(s);
33.2(s); 35.2(s); 55.7(p); 64.9(s); 71.1(s), 72.0(s), 73.6(t), 75.1(s),
101.4(t); 175.5(q).
FT-IR (KBr): 3411 b-w, 2916 w-m, 2849 w-m, 1727 s, 1463
m-s.
Method C: Ionic liquids as solvent. In comparison to Method
A only 1 ml solvent in the form of ionic liquids was used.
m/z (APCI-MS) 405.2 (M-H+, C21H40O7 requires 404.5488).
Melting point (DSC): 71.17 ◦C.
Method D: Ionic liquid film coated lipase beads. Before the
transformation a coating of Novozym 435 beads with ionic
liquids was applied. 500 mg ionic liquid and 10 ml acetonitrile
were mixed in a 100 ml flask and 485 mg Novozym 435 was added
and mixed with the rotavapor for 20 minutes at atmospheric
pressure. The acetonitrile was then removed at reduced pressure
2 kPa/RT. The coated carriers were stocked over night in a
dessicator at room temperature until use the next day. The
transformation effected with no additional solvents (Fig. 1)
corresponds to Method B.
6-O-hexadecanoyl-methyl-a-D-glucopyranoside 3d
dH(400 MHz, CD3OD) 0.91 (3 H, t, J16¢,15¢= 7.2 Hz, CH2CH3),
1.30 (24 H, m, 12xCH2), 1.63 (2 H, m, CH2CH2CH2), 2.35 (2 H,
t, J2¢,3¢= 7.2 Hz, CH2CO), 3.31 (1 H, m, CHOH), 3.37 (1 H, m,
CHOH), 3.41 (3 H, s, OCH3), 3.59 (1 H, m, CHOH), 3.68 (1 H,
m, CHOCH2), 4.21 (1 H, dd, J6b,5=11.6, 6.2 Hz, CH2OCO),
4.37 (1 H, dd, J6a,5 = 12.0, 2.2 Hz, CH2OCO), 4.65 (1 H, d, J1,2
=
4.0 Hz, CHOCH3), 4.86 (3 H, s, 3xOH).
dC(100 MHz; CD3OD) 13.1(p), 22.4(s), 24.7(s), 10 ¥ 29.0(s),
31.7(s), 33.7(s), 54.2(p), 63.4(s), 69.7(s), 70.5(s), 72.09(t), 73.7(s),
99.9(t), 174.0(q).
6-O-decanoyl-methyl-a-D-glucopyranoside 3a
dH(400 MHz, CD3OD) 0.89 (3 H, t, J10¢,9¢ = 6.4 Hz, CH2CH3),
1.3 (12 H, m, 6¥CH2), 1.61 (2 H, m, CH2CH2CH2), 2.34 (2 H,
t, J2¢,3¢ = 7.2 Hz, CH2CO), 3.26 (1 H, m, CHOH), 3.35 (1 H, m,
CHOH), 3.38 (3 H, s, OCH3), 3.60 (1 H, t, CHOH), 3.67 (1 H,
FT-IR (KBr): 3405 b-w, 2916 w-m, 2849 w-m, 1727 s,
1473 m-s.
Melting point (DSC): 86.42 ◦C.
1796 | Green Chem., 2009, 11, 1793–1800
This journal is
The Royal Society of Chemistry 2009
©