SPECIAL TOPIC
8,18,18-Trifluorostearic Acid (7)
Methyl 18,18,18-trifluorooctadec-15-enoate (6) obtained above
was treated with KOH in MeOH (0.9 M, 1 mL) at r.t. for 1 h, then
Trifluoromethyl Derivatization of GM1
Trifluoro-GM1
1907
1
To a solution of N-succinimidyl 18,18,18-trifluorostearate (18 mg,
41 mmol) and lyso-GM1 (27 mg, 21 mmol) in anhyd DMF (2 mL),
was added DIPEA (10 mL). The mixture was stirred at r.t. for 4 h,
then the solvent was evaporated and the residue was purified using
flash column chromatography (CHCl –MeOH–H O, 60:40:5, v/v/
diluted with H O (3 mL) and acidified with 1 M HCl to pH 2. The
2
solution was extracted with Et O (3 × 5 mL), washed with H O
2
2
(
2 × 5 mL) and brine (2 × 5 mL), dried over anhyd Na SO and the
2
4
3
2
solvent was removed in vacuo. The crude material was purified us-
ing flash column chromatography (EtOAc–hexane, 25%) to afford
the pure product (72 mg, 83% over the two steps).
1
v) to give trifluoro-GM1 as a white powder (28 mg, 63%).
19
F NMR (CDCl , 470 MHz): d = –67.81 (t, J = 11.2 Hz).
3
–
ESI-MS: m/z [C H F N O – H] calcd: 1598.8; found: 1599.1;
73 127
3
3
–
31
H NMR (CDCl , 500 MHz): d = 2.38 (t, J = 8.0 Hz, 2 H), 2.08 (m,
3
m/z [C H F N O – H] calcd: 1626.8; found: 1627.1.
7
5
131
3
3
31
2
H), 1.67 (m, 2 H), 1.36 (m, 2 H), 1.28 (s, 24 H).
+
HRMS-ESI: m/z [C H F N O + Na] calcd: 1622.8381; found:
1
3
73 128
3
3
31
C NMR (CDCl , 125 MHz): d = 178.65, 127.32, 36.45, 33.84,
3
1
622.8344.
3
2
0.89, 29.62, 29.59, 29.53, 29.34, 29.17, 29.07, 28.79, 28.70, 24.37,
1.83.
Acknowledgment
N-Succinimidyl 18,18,18-Trifluorostearate (8)
This work was supported in part by the National Institutes of Health
GM65500 and CA125033). The ESI-MS and NMR facilities at
Tufts are supported by the National Science Foundation (0320783
and 0821508).
To a solution of N-hydroxysuccinimide (34.5 mg, 0.30 mmol) and
(
1
8,18,18-trifluorostearic acid (7; 72 mg, 0.21 mmol) in anhyd diox-
ane (5 mL), was added DCC (103 mg, 0.50 mmol) at r.t., and the
mixture was stirred overnight to allow the completion of the reac-
tion. The precipitate was filtered and the solvent was evaporated.
The residue was purified by flash column chromatography (EtOAc–
hexane, 15%) to give the product as a white powder (68 mg, 73%).
1
References
H NMR (CDCl , 500 MHz): d = 2.83 (s, 4 H), 2.60 (t, J = 8.0 Hz,
(1) Singer, S. J.; Nicolson, G. L. Science 1972, 175, 720.
(2) Brown, D. A.; London, E. Annu. Rev. Cell Dev. Biol. 1998,
3
2
H), 2.06 (m, 2 H), 1.74 (m, 2 H), 1.54 (s, 4 H), 1.26 (s, 22 H).
1
4, 111.
3) Simons, K.; Toomre, D. Nat. Rev. Mol. Cell Biol. 2000, 1,
1.
4) Lingwood, D.; Simons, K. Science 2010, 327, 46.
1
3
C NMR (CDCl , 125 MHz): d = 169.11, 168.67, 127.32, 33.85,
3
(
(
3
2
3.62, 30.96, 29.62, 29.59, 29.53, 29.34, 29.17, 29.07, 28.79, 28.70,
5.59, 24.58, 21.85.
3
1
9
F NMR (CDCl , 470 MHz): d = –69.59 (t, J = 11.0 Hz).
(5) Munro, S. Cell 2003, 115, 377.
6) Hancock, J. F. Nat. Rev. Mol. Cell Biol. 2006, 7, 456.
3
(
Deacetyl-lyso-GM1
GM1 (208 mg, 0.13 mmol) was dissolved in KOH in MeOH (0.8 M,
(7) Meng, H.; Krishnaji, S. T.; Beinborn, M.; Kumar, K. J. Med.
Chem. 2008, 51, 7303.
(8) Meng, H.; Kumar, K. J. Am. Chem. Soc. 2007, 129, 15615.
(9) Tang, Y.; Ghirlanda, G.; Petka, W. A.; Nakajima, T.;
DeGrado, W. F.; Tirrell, D. A. Angew. Chem. Int. Ed. 2001,
40, 1494.
(10) Tang, Y.; Ghirlanda, G.; Vaidehi, N.; Kua, J.; Mainz, D. T.;
Goddard, W. A.; DeGrado, W. F.; Tirrell, D. A.
Biochemistry 2001, 40, 2790.
5
0 mL) in a thick-walled reaction tube, and stirred at 100 °C for 2
d. The solvent was removed in vacuo and the resulting residue was
neutralized slowly with AcOH to pH 7.0, and then dialyzed against
H O (2 × 1.0 L). The solution in the dialysis bag after freeze-drying,
2
yielded the crude product (160 mg, 94%).
–
ESI-MS: m/z [C H N O – H] calcd: 1236.6; found: 1236.7; m/z
5
3
94
–
3
29
[
C H N O – H] calcd: 1264.6; found: 1264.7.
55 98 3 29
(
(
11) Salwiczek, M.; Koksch, B. ChemBioChem 2009, 10, 2867.
12) Gottler, L. M.; de la Salud-Bea, R.; Marsh, E. N. G.
Biochemistry 2008, 47, 4484.
N-Fmoc-lyso-GM1
Deacetyl-lyso-GM1 (160 mg, 0.13 mmol) was partitioned in 12 mL
(
(
(
(
13) Buer, B. C.; de la Salud-Bea, R.; Hashimi, H. M. A.; Marsh,
E. N. G. Biochemistry 2009, 48, 10810.
14) Lee, K. H.; Lee, H. Y.; Slutsky, M. M.; Anderson, J. T.;
Marsh, E. N. G. Biochemistry 2004, 43, 16277.
of a 1:1 mixture of aq NaHCO (0.1 M) and Et O and cooled on a
3
2
dry ice bath until the aqueous phase froze. Fmoc-Cl (40 mg, 0.16
mmol) was added and the mixture was stirred at 4 °C for 24 h. TLC
and ESI-MS showed disappearance of the starting materials. Ac O
2
15) Jackel, C.; Salwiczek, M.; Koksch, B. Angew. Chem. Int. Ed.
(
40 mL) was added and the mixture was stirred at 4 °C for 12 h. Af-
2006, 45, 4198.
ter removal of solvent, the residue was purified by flash column
chromatography (CHCl –MeOH–H O, 60:40:5, v/v/v) to give the
16) Chiu, H. P.; Suzuki, Y.; Gullickson, D.; Ahmad, R.; Kokona,
3
2
B.; Fairman, R.; Cheng, R. P. J. Am. Chem. Soc. 2006, 128,
crude product (164 mg, 84%).
15556.
–
ESI-MS: m/z [C H N O – H] calcd: 1500.6; found: 1500.6;
7
0
106
3
32
(17) Zheng, H.; Comeforo, K.; Gao, J. M. J. Am. Chem. Soc.
–
m/z [C H N O – H] calcd: 1528.7; found: 1528.7.
72
110
3
32
2009, 131, 18.
(
18) Niemz, A.; Tirrell, D. A. J. Am. Chem. Soc. 2001, 123, 7407.
Lyso-GM1
(19) Naarmann, N.; Bilgicer, B.; Meng, H.; Kumar, K.; Steinem,
C. Angew. Chem. Int. Ed. 2006, 45, 2588.
(20) Bilgiçer, B.; Kumar, K. Proc. Natl. Acad. Sci. U.S.A. 2004,
N-Fmoc-lyso-GM1 (164 mg, 0.11 mmol) was treated with sat.
NH OH (5.0 mL) and stirred at r.t. for 6 h. TLC and ESI-MS
4
showed complete conversion of the starting material. Upon removal
of solvents under reduced pressure, the resultant residue was puri-
fied by flash column chromatography (CHCl –MeOH–2M ammo-
101, 15324.
(
21) (a) Bilgiçer, B.; Xing, X.; Kumar, K. J. Am. Chem. Soc.
2001, 123, 11815. (b) Bilgiçer, B.; Kumar, K. J. Chem.
Educ. 2003, 80, 1275. (c) Bilgiçer, B.; Kumar, K.
Tetrahedron 2002, 58, 4105.
3
nia, 60:40:5, v/v/v) to afford the pure product (60 mg, 43%).
–
ESI-MS: m/z [C H N O – H] calcd: 1278.6; found: 1278.7; m/z
5
5
96
–
3
30
[
C H N O – H] calcd: 1306.6; found: 1306.7.
(22) Bilgiçer, B.; Fichera, A.; Kumar, K. J. Am. Chem. Soc. 2001,
5
7
100
3
30
123, 4393.
Synthesis 2010, No. 11, 1905–1908 © Thieme Stuttgart · New York