Synthesis of a fluorinated analogue of anticancer active ether lipids

Article abstract of DOI:10.1021/jo0016172

The synthesis of racemic 2′-(trimethylammonium)ethyl-3-hexadecyloxy-2-fluoro-2-(methoxymethyl) -prop-1-yl-phosphate (6), a fluorinated analogue of an anticancer active ether lipid 5 was realized with 3% overall yield in a nine-step synthesis starting from 2-methylene-1,3-propanediol (7) using a bromofluorination as the key step. Both enantiomers of the precursor 8 of the ether lipid 6 were synthesized by lipase-catalyzed desymmetrization of the diacetate 17, either by hydrolysis (83% ee) or by lipase-catalyzed acetylation of the diol 22 (82% ee). The antitumor activity of 6 has been found in an in vivo model of the methylcholanthrene-induced fibrosarcoma of mice.

Full text of DOI:10.1021/jo0016172

2078
J . Org. Chem. 2001, 66, 2078-2084
Syn th esis of a F lu or in a ted An a logu e of An tica n cer Active Eth er
Lip id s
Annegret Burchardt,† Tamiko Takahashi,‡ Yoshio Takeuchi,‡ and Gu¨nter Haufe*,†
Organisch-Chemisches Institut, Westfa¨lische Wilhelms-Universita¨t, Corrensstrasse 40,
D-48149 Mu¨nster, Germany, and Toyama Medical & Pharmaceutical University, Sugitami 2630,
Toyama 930-0194, J apan
haufe@uni-muenster.de
Received November 15, 2000
The synthesis of racemic 2′-(trimethylammonium)ethyl-3-hexadecyloxy-2-fluoro-2-(methoxymethyl)-
prop-1-yl-phosphate (6), a fluorinated analogue of an anticancer active ether lipid 5 was realized
with 3% overall yield in a nine-step synthesis starting from 2-methylene-1,3-propanediol (7) using
a bromofluorination as the key step. Both enantiomers of the precursor 8 of the ether lipid 6 were
synthesized by lipase-catalyzed desymmetrization of the diacetate 17, either by hydrolysis (83%
ee) or by lipase-catalyzed acetylation of the diol 22 (82% ee). The antitumor activity of 6 has been
found in an in vivo model of the methylcholanthrene-induced fibrosarcoma of mice.
In tr od u ction
There has been a steady growth of interest in the
platelet activating factor (R)-1-O-hexadecyl-2-acetyl-sn-
glycero-3-phosphocholine and in many synthetic ether
lipids of related structure because of their cytostatic and
cytotoxic activity.1 Edelfosine (1-O-octadecyl-2-O-methyl-
rac-glycero-3-phosphocholine) 1 is one of the most inves-
tigated of this class of compounds, since it exhibits in
vitro and in vivo cytotoxic activity against numerous
human and murine tumor cell strains.2
Among the many anticancer ether lipids thus far
synthesized, few contain fluorine.3 Brachwitz et al. have
shown that the racemic monofluorinated regioisomers 2
and 3 exhibit cytotoxic activity against the Ehrlich-
Ascites tumor, an activity similar to that of edelfosine
1.4 Exchange of the trimethylammonium group with an
L-serine moiety increases the inhibition of proliferation
of malignant cells of the aforementioned tumor.5
high potency against different tumor cell strains. Tests
of ilmofosine 4 and its oxygen analogue 5, as well as the
C18 homologues, were very promising. The enantiomers
of 4 and 5 showed different activity.2,6
In connection with our ongoing research7 on the
synthesis of monofluorinated analogues of natural prod-
ucts and of biologically active compounds, we became
interested in the synthesis of the ether lipid 6, which
bears a fluorine on its stereogenic center.8
The variation of the substitution pattern around the
stereogenic center of compound 1 led to substances of
* To whom correspondence should be addressed. Phone: 49-251-
83-33281. Fax: 49-251-83-39772.
† Organisch-Chemisches Institut, Westfa¨lische Wilhelms-Universi-
ta¨t.
‡ Toyama Medical & Pharmaceutical University.
(6) Reddy, K. C.; Byun, H.-S.; Bittman, R. Tetrahedron Lett. 1994,
35, 2679-2682. (b) Bittman, R.; Byun, H.-S.; Reddy, K. C.; Samadder,
P.; Arthur, G. J . Med. Chem. 1997, 40, 1391-1395.
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J . Natl. Cancer Inst. 1980, 64, 1301-1306. (b) Fleer, E. A.; Kim, D.-J .;
Nagel, G. A.; Eibl, H.; Unger, C. Onkologie 1990, 13, 295-300. (c)
Hofmann, J .; Utz, I.; Spitaler, M.; Hofer, S.; Rybczynska, M.; Beck,
W. T.; Herrmann, D. B. J .; Grunicke, H. Br. J . Cancer 1997, 76, 862-
869. (d) Grosman, N. Immunopharmacology 1998, 40, 163-171. (e)
Canabar, C.; Gajate, C.; Macho, A.; Munoz, E.; Mododell, M.; Mollinedo,
F. Br. J . Pharmacol. 1999, 127, 813-825. (f) Santa-Rita, R. M.;
Barbosa, H. S.; Meirelles, M. N. L.; Castro, S. L. Acta Trop. 2000, 75,
219-228.
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1998, 31, 511-517.
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Pharm. Unserer Zeit 1986, 15, 107-112 and references therein.
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Phys. Lipids 1982, 31, 33-52. (b) Ostermann, G.; Brachwitz, H.; Till,
U. Biomed. Biochim. Acta 1984, 43, 349-355.
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(b) Sattler, A.; Haufe, G. Tetrahedron: Asymmetry 1995, 6, 2841-2848.
(c) Sattler, A.; Haufe, G. Tetrahedron 1996, 52, 5469-5474. (d) Goj,
O.; Kotila, S.; Haufe, G. Tetrahedron 1996, 52, 12761-12774. (e) Haufe,
G.; Kro¨ger, S. Amino Acids 1996, 11, 409-424. (f) Kro¨ger, S.; Haufe,
G. Amino Acids 1997, 12, 363-372. (g) Kro¨ger, S.; Haufe, G. Liebigs
Ann. 1997, 1201-1206. (h) Skupin, R.; Cooper, T. G.; Fro¨hlich, R.;
Prigge, J .; Haufe, G. Tetrahedron: Asymmetry 1997, 8, 2453-2464.
(i) Laue, K. W.; Haufe, G. Synthesis 1998, 1453-1456. (j) Haufe, G.;
Laue, K. W.; Triller, M. U.; Takeuchi, Y.; Shibata, N. Tetrahedron 1998,
54, 5929-5938. (k) Takeuchi, Y.; Kamezaki, M.; Kirihara, K.; Haufe,
G.; Laue, K. W.; Shibata, N. Chem. Pharm. Bull. 1998, 46, 1062-1064.
(l) Lu, S.-F. Herbert, B.; Haufe, G.; Laue, K. W.; Padgett, W. L.;
Oshunleti, O.; Daly, J . W.; Kirk, K. L. J . Med. Chem. 2000, 43, 1611-
1619. (m) Meyer, O. G. J .; Fro¨hlich, R.; Haufe, G. Synthesis 2000,
1479-1490. (n) Runge, M.; Haufe, G. J . Org. Chem. 2000, 65, 8737-
8742.
(5) (a) Brachwitz, H.; Langen, P.; Lehmann, C.; Matthes, E.; Schildt,
J . Eur. Pat. 1986, 0229128. (b) Brachwitz, H.; Hermetter, A.; Langen,
P.; Matthes, E.; Paltauf, F.; Schildt, J . DD Pat. 1986, 239208; Chem.
Abstr. 1987, 107, 33187x.
(8) Burchardt, A.; Haufe, G. presented in part at the 12th European
Conference on Fluorine Chemistry, Berlin, 1998, abstracts of papers
A 38.
10.1021/jo0016172 CCC: $20.00 © 2001 American Chemical Society
Published on Web 02/21/2001

Fluorinated Anticancer Active Ether Lipids
J . Org. Chem., Vol. 66, No. 6, 2001 2079
Sch em e 1a
Resu lts a n d Discu ssion
Retrosynthetic analysis of the title compound 6 leads
to 2-methylenepropane-1,3-diol 7 via the fluorohydrin 8.
a
Reagents and conditions: (a) NBS/Et3N‚3HF, CH2Cl2,
0 °C f r.t., (b) PhCHO, H+.
Consequently, only one of the hydroxyl functions was
protected with a long chain alkyl group using known
procedures6a,13 to form 2-(hexadecyloxymethyl)-2-propen-
1-ol (14). This species, on bromofluorination with NBS/
Et3N‚3HF at room temperature, gave the bromofluoride
15 in 60% yield. The more reactive system NBS/Me3N‚
3HF at -10 °C gave the desired product 15 in 70% yield.
In both cases, no evidence for other fluorinated com-
pounds were detected by 19F NMR spectroscopy of the
crude products (Scheme 2).
Subsequent nucleophilic substitution of bromine with
acetate using conditions which have been applied to
similar substrates14 gave a 43:10:47 mixture (GC) of the
monoacetate 16a , the diacetate 17a , and the oxetane 18.
Under modified conditions (cf. Experimental Section), the
amount of 18 was minimized to 23% in the best-case
synthesis. The products were separated by column chro-
matography.
The diacetate 17a was available more selectively by
acetylation of 15 with acetic anhydride in pyridine to
form 19. Subsequent nucleophilic substitution of bromide
with acetate gave 17a in 67% overall yield.
The next step of the sequence required the O-meth-
ylation of 16a , followed by the hydrolysis of the acetate
function to 8, the crucial precursor for the synthesis of
the fluorinated ether lipid 6. However, all attempts to
etherify the base-labile 16a , according to procedures15
known for related compounds, failed. Therefore, the OH
group of 16a was protected as a phenylcarbamate, a
functionality which is known to be relatively stable under
basic conditions.16 Subsequent saponification of the ac-
etate group of the thus-formed carbamate 21, yielding
22, followed by methylation of the liberated OH group
and the NH moiety of 22 gave the N-methylated methoxy
compound 23. The carbamate 23 was hydrolyzed by
refluxing with KOH/MeOH to give the precursor 8 of the
racemic title compound 6 in 69% yield. The overall yield
was 8% based on 14 (Scheme 3).
However, the key step of the planned synthesis, the
bromofluorination9 of 7 with N-bromosuccinimide (NBS)
and triethylamine tris(hydrogenfluoride) (Et3N‚3HF),
gave only 30% of the desired bromofluoride 9. Also
observed were nonfluorinated “oligomeric” products formed
by nucleophilic attack of one of the OH groups of a second
molecule of 7 at the cationic intermediate formed from 7
and NBS. Evidence for the regioisomer of 9 or for other
fluorinated compounds was not found in the 19F NMR
spectrum of the crude reaction product. Bromofluorina-
tion of allyl alcohol10 and of other allylic compounds11
gave both regioisomers (Scheme 1).
To remove the competition of the OH functions and the
fluoride donor for the intermediate cation, the free
hydroxyl groups of 7 were protected with benzaldehyde.
The bromofluorination of the thus-formed 1,3-dioxane
1026 gave both regioisomeric bromofluorides 11 and 12,
but the unwanted isomer 12 was the main product. We
also obtained some amount of the dibromide 13.27 Dibro-
mides, arising from Br2 accumulation, are known to be
formed under bromofluorination conditions, particularly
when the double bond is unreactive and the fluorinating
agent is relatively nucleophilic.11h,12
(9) (a) Alvernhe, G.; Laurent, A.; Haufe, G. Synthesis 1997, 562-
564. (b) Haufe, G.; Alvernhe, G.; Laurent, A.; Ernet, T.; Goj, O.; Kro¨ger,
S.; Sattler, A. Org. Synth. 1999, 76, 159-168.
(10) Chehidi, I.; Chaabouni, M.; Baklouti, A. Tetrahedron Lett. 1989,
30, 3167-3170.
(11) (a) De la Mare, P. B. D.; Naylor, P. G.; Wiliams, D. L. H. J .
Chem. Soc. 1963, 3429-3436. (b) Pattison, F. L. M.; Peters, D. A. V.;
Dean, F. H. Can. J . Chem. 1965, 43, 1689-1699. (c) Dolbier, W. R.,
J r.; Gray, T. A.; Keaffaber, J . J .; Celewicz, L.; Koroniak, H. J . Am.
Chem. Soc. 1990, 112, 363-367. (d) Fujita, M.; Ishizuka, H.; Ogura,
K. Tetrahedron Lett. 1991, 32, 6355-6358. (e) Hedhli, A.; Baklouti, A.
J . Org. Chem. 1994, 59, 5277-5278. (f) Haufe, G.; Wessel, U.; Schulze,
K.; Alvernhe, G. J . Fluorine Chem. 1995, 74, 283-291. (g) Limat, D.;
Guggisberg, Y.; Schlosser, M. Liebigs Ann. Chem. 1995, 849-853. (h)
Lu¨bke, M.; Skupin, R.; Haufe, G. J . Fluorine Chem. 2000, 102, 125-
135.
(12) (a) Alvernhe, G.; Anker, D.; Saluzzo, C.; Laurtent, A.; Haufe,
G.; Beguin, C. Tetrahedron 1988, 44, 3551-3563. (b) Camps, F.;
Chamorro, E.; Gasol, V.; Guerrero, A. J . Org. Chem. 1989, 54, 4294-
4298.
(13) (a) Bauer, F.; Ruess, K.-P.; Liefla¨nder, M. Liebigs Ann. Chem.
1991, 765-768. (b) Roelens, S. J . Org. Chem. 1996, 61, 5257-5263.
(14) (a) Goj, O.; Haufe, G. Liebigs Ann. 1996, 1289-1294. (b) Goj,
O.; Kotila, Haufe, G. Tetrahedron 1996, 52, 12761-12774.
(15) Bonner, W. A. J . Am. Chem. Soc. 1951, 73, 3126-3132. (b) Cole,
W. G.; Williams, D. H. J . Chem. Soc. C 1968, 1849-1852. (c) Walkup,
R. D.; Cunningham, R. T. Tetrahedron Lett. 1987, 28, 4019-4022.
(16) Greene, T. W.; Wuts, P. G. M. Protective Groups in Organic
Synthesis; 2nd ed., J ohn Wiley & Sons: New York, 1991.

2080 J . Org. Chem., Vol. 66, No. 6, 2001
Burchardt et al.
Sch em e 2a
a
Reagents and conditions: (a) NBS/Alk3N‚3HF, CH2Cl2, 0 °C f rt, (b) KOAc, DMF, 24 h reflux, (c) Ac2O, pyridine, r.t., (d) KOH,
MeOH, r.t., 4 h.
Sch em e 3a
Without this cosolvent, a small amount of the monoac-
etate 16a was detected in the product mixture. Mainly
starting material 17a and the diol 20 were found after
24 h of reaction time. The lipase from Pseudomonas
cepacia (Amano PS) was shown to be the most effective
enzyme of those investigated, giving a 30% isolated yield
of the desired optically active product 16a ([R]20D ) -3.6)
after 6.5 h of reaction time. Additionally, 45% of the diol
20 and 20% of starting material 17a were isolated by
column chromatography (Table 1).
To enhance the yield of the monoacetate 16a , we next
examined the reverse process, that is, the lipase-
catalyzed acetylation of the diol 20. As mentioned above,
the deracemization of â-fluorohydrins containing a pri-
mary hydroxyl function and a tertiary fluorine substitu-
ent has been previously realized.18 Recently the Takeuchi
group21 and others22 were able to desymmetrize 2-fluoro-
1,3-propanediols.
The reaction of 20 with 2 equiv of vinyl acetate and
CAL in toluene gave a 44% isolated yield of 16a and a
12% yield of the diacetate 17a . The starting material was
also isolated (23% recovery). The monoacetate 16a did
not show any optical rotation. The esterification using
vinyl chloroacetate and CAL gave partially the monoester
16b (isolated in 32% yield), which was also optically
inactive (Scheme 5).
a
Reagents and conditions: (a) PhNCO, petroleum ether, 110
°C, 10 h, (b) KOH, MeOH, r.t., 2 h, (c) KOH, DMSO, MeI, r.t., 90
min, (d) KOH, MeOH, reflux, 14 h.
To synthesize the enantiomers of 8, we tested several
lipases for deracemization by acetylation in organic
solvents. The best result obtained was a 23% ee for the
unreacted 8 and 32% ee for the acetate thus formed.17
We therefore decided to attempt the desymmetrization
of 17a by enzymatic hydrolysis. We also pursued the
desymmetrization of the diol 20, obtained from 17a by
saponification with methanolic KOH (80% yield, Scheme
3), by lipase-catalyzed acetylation.
In 1997 the Haufe group first succeeded in the catalytic
deracemization of fluorinated acetates by using lipase
from Pseudomonas cepacia (Amano PS).18 These acetates
bore a tertiary fluorine substituent at the stereogenic
center along with a vicinal primary acetate function.
Several deracemizations of â-fluorohydrins bearing a
secondary hydroxyl function have been described.19 There
is little in the literature about lipase-catalyzed hydrolyses
of substrates having an alkoxymethylene group attached
to the stereogenic center.7b,20 Fluorinated compounds of
this type have, to our knowledge, never been investigated.
We therefore first screened several lipases for their
ability to desymmetrize 17a or 20 (Table 1) (Scheme 4).
Porcine pancreatic lipase (PPL) and Candida rugosa
lipase (CRL) gave unsatisfactory transformation of 17a
even after 75 days or 11 days, respectively. Candida
antarctica lipase (CAL) did not significantly hydrolyze
the diacetate 17a when THF was present in the mixture.
The reaction of 20 with immobilized Pseudomonas
cepacia lipase was very slow with 2 equiv of vinyl acetate
in toluene. We therefore decided to use vinyl acetate as
both substrate and solvent. This resulted, after a 3 h
reaction time, in a product mixture consisting of 4% of
starting material 20, 73% of the monoacetate 16a , and
23% of the diacetate 17a (GC analysis). The optically
active 16a ([R]20D ) +3.3) was isolated in 71% yield (Table
2).
In conclusion, the enantiomers of the monoacetate 16a
were formed either by Pseudomonas cepacia lipase-
catalyzed hydrolysis of the diacetate 17a or by acetylation
of the diol 20.
It was very difficult to determine the enantiomeric
excess of the isolated products. We examined the product
16a by 1H and 19F NMR spectroscopy using different shift
reagents such as Eu(hfc)3 or Eu(facam)3. No line separa-
tion was obtained even after the addition of 150 mol %
of the shift reagent. With 20 mol % of Pr(hfc)3, a high
(17) Burchardt, A. Ph.D. Thesis, University of Muenster, 1999.
(18) Goj, O.; Burchardt, A.; Haufe, G. Tetrahedron: Asymmetry
1997, 8, 399-408.
(19) (a) Kitazume, T.; Asai, M.; Lin, J . T.; Yamazaki, T. J . Fluorine
Chem. 1987, 35, 477-488. (b) Yamazaki, T.; Ichikawa, S.; Kitazume,
T. J . Chem. Soc., Chem. Commun. 1989, 253-255.
(21) Yokoyama, H.; Hyodo, R.; Nakada, A.; Yamaguchi, S.; Hirai,
Y.; Kometani, T. Goto, M.; Shibata, N.; Takeuchi, Y. Tetrahedron Lett.
1998, 39, 7741-7744.
(22) Guanti, G.; Narisano, E.; Riva, R. Tetrahedron: Asymmetry
1998, 9, 1859-1862.
(20) Kazlauskas, R. J .; Weissfloch, A. N. E.; Rappaport, A. T.; Cuccia,
L. A. J . Org. Chem. 1991, 56, 2656-2665 and references therein.

Fluorinated Anticancer Active Ether Lipids
J . Org. Chem., Vol. 66, No. 6, 2001 2081
Ta ble 1. Lip a se-Ca ta lyzed Hyd r olyses of th e Dia ceta te 17a
entry
17a [mg]
THF [ml]
enzyme [mg]
time
17a mg, [%]a(%)b
16a mg, [%]a(%)b
20 mg [%]a(%)b
1
2
3
4
5
160
100
100
200
100
3
2
2
-
PPL (200)
CRL (5)
CAL (5)
CAL (20)
Amano PS (5)
75 d
11 d
48 h
24 h
6.5 h
120 [84] (78)
70 [87] (71)
90 [100] (91)
95 [51] (48)
20 [26] (18)
10 [13] (7)
7 [11] (8)
-
2 [3] (<2)
2 [2] (<2)
-
61 [44] (38)
36 [45] (45)
5 [5] (3)
2
30 [29] (30)c
a
b
Part of the product mixture, GC. Isolated yield. c [R]20 ) -3.6, c ) 1.1 in chloroform (83% ee).24
D
Sch em e 4a
Sch em e 6a
a
Reagents and conditions: (a) Lipase, THF, 0.1 M phosphate
buffer, pH 7.0, r.t.
Sch em e 5a
a
Reagents and conditions: (a) (i) 2-chloro-2-oxo-1,3-dioxa-2-
phospholane, Et3N, THF, r.t., (ii) Me3N, MeCN, 60 °C, sealed tube,
72 h.
The racemic fluoro alcohol 8 was transformed to the
desired analogue 6 of the ether lipid 5 analogously to the
method described by Guivisdalsky and Bittman.25
The fluorohydrin 8 was treated with a 3-fold excess of
2-chloro-2-oxo-1,3-dioxa-2-phospholane and triethylamine
in THF at room temperature. The crude phosphoric acid
triester intermediate was subsequently heated with
trimethylamine in acetonitrile at 60 °C in a sealed tube
for 72 h. The resulting phosphocholine derivative 6 was
isolated in 35% yield. The overall yield of 6 was 3% based
on 14 (Scheme 6).
The anticancer activity of 6 was tested in an in vivo
model of the methylcholanthrene induced fibrosarcoma
of mice. The activity of 6 was compared to that of cisplatin
and ilmofosine. While a significant antitumor activity
(IC50 1.13 mg/mL, 48 h incubation time) of 6 was found,
this activity was lower than that of cisplatin (IC50 0.17
mg/mL) or ilmofosine (IC50 0.23 mg/mL), all measured
under the same experimental protocol.
a
Reagents and conditions: (a) Lipase, toluene, vinyl acetate or
vinyl chloroacetate, respectively.
field shift resulting in the partial separation of the methyl
signals of the acetoxy function of 16a was observed. With
a higher concentration of the shift reagent, line broaden-
ing and overlap of the signals in the aliphatic part of the
1H NMR spectrum were observed. No line separation was
observed in the 19F NMR spectra.
Another strategy for the NMR spectroscopic determi-
nation of the enantiomeric excess of chiral alcohols is the
transformation of these alcohols into diastereomeric
esters.23 In this case 19F NMR spectroscopy may be
particularly useful because the shift differences of the
relevant diastereomers are usually bigger than in the
1
corresponding H NMR spectra, and overlap of signals
is rarely observed. We therefore used (1S)-(-)-camphanic
acid chloride, (1S)-(-)-camphorsulfonic acid chloride, and
(S)-(+)-chloropropanoic acid chloride as derivatizing re-
agents, but no signal separation was found in either the
1H or the 19F NMR spectra. After derivatization of 16a
with (R)-(+)-R-methoxy-R-trifluoromethylphenylacetic acid
(Mosher’s acid), no line separation was observed in the
product 19F spectrum. When (S)-(+)-methoxymandelic
acid was used as the derivatizing agent, a small shift-
difference of 0.06 ppm was found in 1H NMR of the
methoxy groups of the product, but the signals could not
be baseline resolved. Consequently, an exact integration
of the signals was impossible using these methods. We
succeeded in the determination of the enantiomeric
excess of 16a using the new derivatizing reagent R-cyano-
R-fluoro(2-naphthyl)acetic acid (2-CFNA), which we re-
cently described.24 By using 2-CFNA, it was found that
the product 16a , obtained by hydrolysis of 17a using
lipase Amano PS (Table 1, entry 5), had an 83% ee (19F
NMR).
Exp er im en ta l Section
1
Gen er a l. IR spectra, KBr pellets, ν˜ [cm-1]. H NMR (300.1
MHz), 13C NMR (75.5 MHz), and 19F NMR (282.3 MHz) were
recorded from ca. 20% solutions in CDCl3 (if not stated
otherwise). Chemical shifts are reported as δ values [ppm]
relative to TMS (1H), CDCl3 (13C), or CFCl3 (19F), respectively,
as internal standards. For 31P NMR (121.5 MHz), 80%
phosphoric acid was used as an external standard. The
multiplicity of 13C signals was determined by the DEPT
operation. Mass spectra (electron impact ionization, 70 eV)
were recorded by GC/MS coupling. The composition of crude
reaction products and the conversion of substrates during
enzymatic transformations was followed by GC using quartz
capillary columns, 25 m × 0.33 mm, 0.52 µm HP-1 (Hewlett-
Packard) and 30 m × 0.32 mm, 0.25 µm SPB-1 (Supelco),
(25) Guivisdalsky, P. N.; Bittman, R. J . Org. Chem. 1989, 54, 4637-
4642.
(26) Weiss, F.; Isard, A.; Bensa, R. R. Bull. Soc. Chim. Fr. 1965,
1355-1358.
(23) Parker, D. Chem. Rev. 1991, 91, 1441-1457.
(24) Takahashi, T.; Fukushima, A.; Tanaka, Y.; Segawa, M.; Hori,
H.; Takeuchi, Y.; Burchardt, A.; Haufe, G. Chirality 2000, 12, 458-
463.
(27) (a) Vadecard, J .; Plaquevent, J .-C.; Duhamel, L.; Duhamel, P.
J . Org. Chem. 1994, 59, 2285-2286. (b) Amadij, M.; Vadecard, J .;
Schimmel, U.; Ple, G.; Plaquevent, J .-C. J . Chem. Res. 1995, 362-
363.

2082 J . Org. Chem., Vol. 66, No. 6, 2001
Ta ble 2. Lip a se-Ca ta lyzed Acetyla tion of th e Diol 20
Burchardt et al.
20
[mg]
toluene
(mL)
enzyme
(mg)
acylation reagent
(mg)
product
mixture
compositiona
[%]
yield
[mg] (%)
entry
1
time
12 h
[R]20
D
CAL
(40)
vinyl
acetate
(51)
vinyl
chloroacetate
(49)
20
30
54
16
40
47
13
4
46 (23)
100 (44)
30 (12)
50 (35)
56 (32)
20 (10)
5 (2)
-
0
-
-
0
-
200
140
200
23
16
-
16a
17a
20
16b
17b
20
CAL
(28)
2
4 d
3 h
immobil.
Amano
PS (97)
vinyl
-
3
acetateb
(4 mL)
16a
17a
73
23
160 (71)
45 (19)
+3.3c
-
a
b
Part of the product mixture, GC. Used as the solvent. c c ) 1.06 in chloroform.
temperature program, 40 °C f 280 °C with a 10 °C/min
heating rate, N2 as the carrier gas. The ratio of compounds
was determined by integration of the peak areas. - The
products, including those of enzymatic transformations, were
separated by column chromatography (silica gel, Merck 60,
70-230 mesh). Optical rotations were measured at the NaD
line (λ ) 589 nm). Enantiomeric excesses were measured as
described in ref 24. Microanalyses were carried out by the
“Mikroanalytisches Laboratorium, Organische Chemie”, Uni-
versity of Mu¨nster using a CHNO analyzer.
2-F lu or o-2-(h exa d ecyloxym eth yl)oxeta n e (18). Yield:
1
90 mg (21%). Mp 34 °C (pentane/diethyl ether 5:1). H NMR:
δ 0.88 (t, 3J H,H ) 6.5 Hz, 3 H), 1.22-1.38 (m, 26 H), 1.54-1.63
(m, 2 H), 3.52 (t, 3J H,H ) 6.6 Hz, 2 H), 3.76 (d, 3J H,F ) 21.0 Hz,
2
3
2 H), 4.60 (ABX, J H,H ) 8.1 Hz, J H,F ) 18.1 Hz, 2H), 4.77
(ABX, J H,H ) 8.1 Hz, J H,F ) 19.3 Hz); 13C NMR: δ 14.1 (q),
22.7 (t), 26.0 (t), 29.3 to 29.8 (11t), 31.9 (t), 71.3 (dt, J C,F
2
3
2
)
)
2
1
25.4 Hz), 72.3 (t), 78.6 (dt, J C,F ) 25.4 Hz), 93.7 (ds, J C,F
208.5 Hz); 19F NMR: δ -155.9 (ttt, J H,F ) 19.1 Hz); Mass
spectrum, m/z (%): 331 (0.02), 299 (1), 279 (4), 253 (6), 239
(3), 224 (16), 196 (12), 161 (17), 153 (7), 139 (14), 125 (28), 119
(41), 111 (57), 107 (94), 99 (28), 98 (24), 97 (20), 96 (38), 89
(13), 85 (75), 84 (50), 83 (100), 82 (81), 71 (100), 70 (78), 69
(100), 68 (92). Anal. Calcd for C20H39FO2 (330.52): C, 72.68;
H, 11.89. Found C, 72.88; H, 12.07.
3
Br om oflu or in a tion of 2-(Hexa d ecyloxym eth yl)-2-p r o-
p en -1-ol (14). A solution of 14 (770 mg, 2.46 mmol) prepared
according to ref 13 and Me3N‚3HF (400 mg, 3.81 mmol) in
dichloromethane (10 mL) was treated with NBS (481 mg, 2.70
mmol) in portions at -10 °C and stirred for 17 h. Subsequently
the mixture was poured into ice-water (50 mL) and neutral-
ized with 26% aq ammonia. The organic layer was separated,
and the aqueous layer was extracted with ethyl acetate. The
combined organic layer was washed with 0.1 N hydrochloric
acid followed by 5% aq sodium bicarbonate solution and dried
over magnesium sulfate. The solvent was evaporated, and the
residue was purified by column chromatography (pentane/
diethyl ether, 5:1) to obtain 3-bromo-2-fluoro-2-(hexadecyl-
oxymethyl)-propan-1-ol (15) as white crystals. Yield: 708 mg
(70%). Mp 39 °C (pentane/diethyl ether 5:1).1H NMR: δ 0.88
Acetyla tion of 3-Br om o-2-flu or o-2-(h exa d ecyloxy-
m eth yl)p r op a n -1-ol (15). A solution of 15 (400 mg, 0.97
mmol), acetic anhydride (102 mg, 1 mmol), and pyridine (79
mg, 1 mmol) was stirred for 15 h at room temperature. Ice-
water (5 mL) was added, and the mixture was extracted with
dichloromethane. The combined organic layer was washed with
10% aq HCl, followed by water, and dried over magnesium
sulfate. After evaporation of the solvent, the crude product was
purified by column chromatography (pentane/diethyl ether 10:
1), to give 1-acetoxy-3-bromo-2-fluoro-2-(hexadecyloxymethyl)-
propane (19) as a white solid. Yield: 417 mg (95%). Mp 39 °C
3
(t, J H,H ) 6.5 Hz, 3 H), 1.21-1.39 (m, 26 H), 1.52-1.62 (m, 2
3
1
3
H), 2.00 (s, 1 H), 3.49 (t, J H,H ) 6.4 Hz, 2 H), 3.60-3.90 (m, 6
(pentane/diethyl ether, 10:1). H NMR: δ 0.88 (t, J H,H ) 6.7
H);13C NMR: δ 14.1 (q), 22.7 (t), 26.0 (t), 29.4 to 29.7, (11t),
Hz, 3 H), 1.22-1.38 (m, 26 H), 1.51-1.60 (m, 2 H), 2.11 (s, 3
2
2
3
31.1 (dt, J C,F ) 28.0 Hz), 31.9 (t), 64.0 (dt, J C,F ) 25.4 Hz),
H), 3.48 (t, J H,H ) 6.4 Hz, 2 H), 3.50-3.74 (m, 4 H), 4.35 (d,
2
1
3J H,F ) 19.6 Hz, 2 H); 13C NMR: δ 14.1 (q), 20.7 (q), 22.7 (t),
70.7 (dt, J C,F ) 28.0 Hz), 72.3 (t), 95.1 (ds, J C,F ) 175.5 Hz);
19F NMR: δ -169.0 (ttt, 3J H,F ) 17.2 Hz); Mass spectrum (after
silylation), m/z (%): 482/484 (0.2), 467/469 (1), 403 (1), 384
(9), 383 (40), 243/245 (9), 159 (30), 143 (59), 133 (60), 103 (46),
99 (9), 98 (9), 85 (37), 83 (19), 73 (38), 76 (13), 71 (57), 69 (29).
Anal. Calcd for C20H40BrFO2 (411.44): C, 58.37; H, 9.80. Found
C, 58.37; H, 9.87.
2
26.0 (t), 29.4 to 29.7 (11t), 31.1 (dt, J C,F ) 28.0 Hz), 31.9 (t),
2
2
64.1 (dt, J C,F ) 22.9 Hz), 70.0 (dt, J C,F ) 25.4 Hz), 72.3 (t),
93.9 (ds, J C,F ) 180.6 Hz), 170.1 (s); 19F NMR: δ -166.8 (ttt,
1
3J H,F ) 17.2 Hz); Mass spectrum, m/z (%): 452/454 (0.04), 409/
411 (1), 373 (7), 353 (28), 289 (4), 255 (17), 229/231 (7), 225
(6), 209/211 (7), 181/183 (5), 129 (64), 113 (21), 111 (10), 99
(12), 97 (20), 85 (41), 83 (25), 71 (62), 70 (23), 69 (32). Anal.
Calcd for C22H42BrFO3 (453.47): C, 58.27; H, 9.34. Found C,
58.27; H, 9.34.
Nu cleoph ilic Su bstitu tion of 3-Br om o-2-flu or o-2-(h exa-
d ecyloxm eth yl)p r op a n -1-ol (15) w ith Aceta te. A mixture
of 15 (580 mg, 1.14 mmol) and potassium acetate (894 mg,
9.12 mmol) in dry DMF (5 mL) was refluxed for 24 h. After
cooling the reaction mixture to room temperature, a 1:1
mixture of cyclohexane/ethyl acetate (5 mL) was added, and
the precipitated potassium bromide was filtered off. The
organic layer was washed with water and dried over magne-
sium sulfate, and the solvent was vacuum evaporated. Gas
chromatographic analysis of the crude product showed a
mixture of 15 (5%), 16a (56%), 17a (7%), and 18 (32%). This
mixture was separated by column chromatography to give pure
compounds 16a and 18. Unfortunately, 17a was obtained in
fractions either together with 16a or 18, but 17a was shown
to be identical with an authentic sample obtained in another
way (see below). Refluxing 15 with 4 equiv of KOAc for 24 h
gave 16a (43%), 17a (10%), and 18 (47%). Heating of 15 with
8 equiv of KOAc at 100 °C for 90 h gave a 27:50:23 mixture,
respectively, of these compounds.
1,3-Dia cet oxy-2-flu or o-2-(h exa d exyloxym et h yl)p r o-
p a n e (17a ). A mixture of 19 (340 mg, 0.75 mmol) and
potassium acetate (170 mg, 3 mmol) in dimethyl formamide
(5 mL) was refluxed for 24 h. After cooling this reaction
mixture to room temperature, a cyclohexane/ethyl acetate
mixture (1:1, 5 mL) was added, and the precipitate thus formed
was filtered off. The organic layer was washed with water and
dried over magnesium sulfate. After the solvent was removed,
the crude product was purified by column chromatography
(pentane/diethyl ether, 3:1) to give pure 17a as a white solid.
Yield: 427 mg (70%). Mp 38 °C (pentane/diethyl ether 5:1);
1H NMR: δ 0.88 (t, 3J H,H ) 6.7 Hz), 1.20-1.34 (m, 26 H), 1.50-
3
1.60 (m, 2 H), 2.10 (s, 6 H), 3.46 (t, J H,H ) 6.4 Hz, 2 H), 3.62
(d, 3J H,F ) 16.6 Hz, 2 H), 4.23-4.38 (m, 4 H); 13C NMR: δ 14.1
(q), 20.6 (2q), 22.6 (t), 26.0 (t), 29.3 to 29.6 (11t), 31.9 (t), 63.1
2
2
(2dt, J C,F ) 25.4 Hz), 69.5 (dt, J C,F ) 28.0 Hz), 72.3 (t), 94.1
(ds, 1J C,F ) 180.6 Hz), 170.2 (2s); 19F NMR: δ -174.1 (m); Mass
spectrum, m/z (%): 432 (1), 373 (1), 352 (8), 310 (31), 292 (8),
281 (4), 269 (2), 209 (14), 191 (16), 149 (46), 129 (6), 118 (47),
87 (12), 86 (14), 85 (18), 83 (14), 81 (12), 71 (14), 69 (16). Anal.
3-Acetoxy-2-flu or o-2-(h exa d ecyloxym eth yl)p r op a n -1-
ol (16a ). Yield: 220 mg (43%). Mp 32 °C (pentane/diethyl ether
1:1). All spectroscopic data agree with those given for the
optically active compound in ref 24.

Fluorinated Anticancer Active Ether Lipids
J . Org. Chem., Vol. 66, No. 6, 2001 2083
Calcd for C24H45FO5 (432.61): C, 66.63; H, 10.48. Found C,
66.89; H, 10.49.
2-F lu or o-2-(h exa d ecyloxym eth yl)-1-m eth oxy-3-(p h en -
yl-N-m eth ylca r ba m oyl)p r op a n e (23). A suspension of pow-
dered potassium hydroxide (35 mg, 0.64 mmol) and dimethyl
sulfoxide (5 mL) was stirred for 10 min at room temperature.
At this temperature 22 (40 mg, 0.09 mmol) and methyl iodide
(45 mg, 0.32 mmol) were added, and the resulting mixture was
stirred for 90 min. At the end of this time, the mixture was
poured into a brine solution (10 mL), and this mixture was
extracted with diethyl ether. The combined extract was washed
with water and dried over magnesium sulfate. After evapora-
tion of the solvent, the residue was purified by column
chromatography (pentane/diethyl ether, 3:1) to obtain 23 as
colorless viscous oil. Yield: 30 mg (67%). IR ν˜ 2923 and 2852
(s), 1716 (s), 1598 (w), 1498 and 1456 (m), 1351 (m), 1276 (w),
1160 (m), 1114 (m), 770 (w), 658 (m); 1H NMR: δ 0.88 (t,
3J H,H ) 6.7 Hz, 3 H), 1.21-1.35 (m, 26 H), 1.46-1.53 (m, 2 H),
Sa p on ifica tion of 1,3-Dia cetoxy-2-flu or o-2-(h exa d ec-
yloxym eth yl)p r op a n e (17a ). A solution of 17a (280 mg, 0.65
mmol) and potassium hydroxide (232 mg, 4 mmol) in methanol
(5 mL) was stirred at room temperature for 4 h. The mixture
was poured into water (10 mL) and extracted with diethyl
ether. The combined ethereal extract was washed with water,
dried over magnesium sulfate, and filtered through silica gel
(3 cm). After evaporation of the solvent, the diol 20 was
1
obtained as a white solid. Yield: 173 mg (80%); H NMR: δ
3
0.88 (t, J H,H ) 6.7 Hz, 3 H), 1.26 (m, 26 H), 1.50-1.60 (m, 2
3
3
H), 2.26 (s, 2 H), 3.48 (t, J H,H ) 6.6 Hz), 3.60 (d, J H,F ) 16.9
Hz), 3.76 (dd, J H,H ) 4.5 Hz, J H,F ) 17.9 Hz, 4 H). 13C NMR
2
3
δ 14.1 (q), 22.7 (t), 26.0 (t), 29.4 to 29.7 (11t), 31.9 (t), 63.4
2
2
(2dt, J C,F ) 25.4 Hz), 70.9 (dt, J C,F ) 28.0 Hz), 72.4 (t), 96.5
3
3.31 (s, 6 H), 3.35-3.48 (m, 6 H), 4.31 (d, J H,F ) 19.8 Hz, 2
(ds, J C,F ) 172.9 Hz); 19F NMR: δ -177.4 (tq, J H,F ) 17.2
Hz); Mass spectrum, m/z (%): 348 (0.6), 328 (8), 297 (28), 255
(3), 253 (4), 241 (6), 225 (6), 224 (5), 196 (4), 167 (4), 155 (4),
125 (67), 111 (18), 97 (33), 85 (41), 83 (35), 71 (60), 70 (28), 69
(42). Anal. Calcd for C20H41FO3 (348.54): C, 68.92; H, 11.86.
Found C, 69.20; H, 12.16.
1
3
H), 7.19-7.38 (m, 5 H); 13C NMR: δ 14.1 (q), 22.6 (t), 26.0 (t),
2
29.3 to 29.6 (11t), 31.9 (t), 37.7 (q), 59.6 (q), 64.8 (t, J C,F
)
2
2
25.4 Hz), 69.6 (t, J C,F ) 25.4 Hz), 71.7 (t, J C,F ) 22.9 Hz),
1
72.1 (t), 95.8 (ds, J C,F ) 180.6 Hz), 125.9 (d), 126.3 (d), 128.8
(d), 143.1 (s), 154.0 (s); 19F NMR: d -173.5 (ttt, J H,F ) 19.1
3
Hz); Mass spectrum (direct inlet), m/z (%): 496 (22), 495 (66),
271 (12), 254 (9), 235 (6), 225 (1), 224 (2), 167 (1), 155 (3), 151
(11), 149 (7), 141 (3), 140 (1), 139 (2), 135 (10), 134 (100), 121
(14), 120 (14), 107 (21), 106 (38), 101 (96), 99 (14), 97 (15), 94
(11), 85 (63), 84 (21), 83 (24), 77 (18), 71 (76), 69 (37). Anal.
Calcd for C29H50FNO4 (495.70): C, 70.27; H, 10.17; N, 2.83.
Found C, 70.27; H, 10.27; N, 3.00.
1-Acetoxy-2-flu or o-2-(h exa d ecyloxym eth yl)-3-(p h en yl-
ca r ba m oyl)p r op a n e (21). A solution of 16a (140 mg, 0.36
mmol) in dry petroleum ether (110 °C, 2 mL) was treated
(syringe) with phenyl isocyanate (54 mg, 0.45 mmol) and
refluxed for 10 h. At 0 °C the white solid 21 precipitated. This
solid was purified by column chromatography (pentane/diethyl
ether, 3:1). Yield: 150 mg (82%). Mp 64 °C (pentane/diethyl
ether, 3:1); IR: ν˜ 3344 (br), 2913 and 2848 (s), 1739 (s), 1707
(s), 1604 (m), 1541 (s), 1472 and 1446 (m), 1318 (m), 1242 (s),
2-F lu or o-2-(h exa d ecyloxym eth yl)-3-m eth oxyp r op a n -1-
ol (8). A solution of 23 (20 mg, 0.04 mmol) and potassium
hydroxide (14 mg, 0.24 mmol) in methanol (2 mL) was refluxed
for 14 h. After cooling, the solution was poured into water (10
mL) and extracted with diethyl ether. The combined extract
was washed with water and dried over magnesium sulfate.
The solvent was evaporated to give 8 as a viscous oil which
1
1128 (m), 1088 (m), 1073 (m), 1051 (m), 688 (m); H NMR: δ
3
0.88 (t, J H,H ) 6.7 Hz, 3 H), 1.22-1.38 (m, 26 H), 1.50-1.60
3
(m, 2 H), 2.09 (s, 3 H), 3.46 (t, J H,H ) 6.5 Hz, 2 H), 3.62 (d,
3J H,F ) 16.0 Hz, 2 H), 4.26-4.45 (m, 4 H), 6.77 (s, 1 H), 7.05-
7.09 (m, 1 H), 7.25-7.39 (m, 4 H); 13C NMR: δ 14.1 (q), 20.6
1
was 90% pure (GC). Yield: 10 mg (69%). H NMR: δ 0.88 (t,
2
(q), 22.6 (t), 26.0 (t), 29.3 to 29.6 (11t), 31.9 (t), 63.1 (t, J C,F
)
3J H,H ) 6.8 Hz, 3 H), 1.20-1.38 (m, 26 H), 1.52-1.61 (m), 2.30
2
2
25.4 Hz), 63.8 (t, J C,F ) 25.4 Hz), 69.6 (t, J C,F ) 25.4 Hz),
(br s, 1 H), 3.40 (s, 3 H), 3.48 (t, 3J H,H ) 6.6 Hz, 2 H), 3.62 and
1
72.3 (t), 94.3 (ds, J C,F ) 183.1 Hz), 118.8 (d), 123.7 (d), 129.1
3
3
3.65 (2 d, J H,F ) 19.3 Hz, J H,F ) 18.4 Hz, 4 H), 3.80 (d,
(d), 137.5 (s), 152.6 (s), 170.2 (s); 19F NMR: δ -174.0 (m); Mass
spectrum (direct inlet), m/z (%): 510 (4), 509 (13), 225 (2), 169
(2), 167 (9), 155 (5), 153 (3), 149 (16), 129 (10), 127 (4), 125
(10), 120 (11), 119 (100), 99 (15), 98 (7), 97 (20), 96 (8), 93 (6),
91 (19), 85 (22), 83 (25), 82 (9), 73 (13), 71 (36), 70 (20), 69
(31), 68 (7). Anal. Calcd for C29H48FNO5 (509.70): C, 68.34;
H, 9.49; N, 2.75. Found C, 68.27; H, 9.54; N, 2.96.
3J H,F ) 16.9 Hz, 2 H); 13C NMR: δ 14.1 (q), 22.7 (t), 26.0 (t),
2
29.3 to 29.7 (11t), 31.9 (t), 59.7 (q), 63.6 (dt, J C,F ) 25.4 Hz),
2
2
70.6 (dt, J C,F ) 25.4 Hz), 72.3 (t), 72.6 (dt, J C,F ) 25.4 Hz),
96.5 (ds, J C,F ) 175.5 Hz); 19F NMR: δ -174.7 (ttt, J H,F
)
1
3
19.1 Hz); Mass spectrum, m/z (%): 362 (0.2), 342 (4), 311 (44),
297 (14), 267 (3), 253 (2), 241 (3), 225 (2), 169 (1), 155 (3), 139
(49), 121 (17), 111 (10), 101 (14), 100 (21), 97 (21), 90 (17), 89
(25), 88 (18), 87 (63), 85 (41), 84 (21), 83 (31), 71 (86), 70 (25),
69 (60). Anal. Calcd for C21H43FO3 (362.56): C, 69.57; H, 11.95.
Found C, 69.56; H, 11.82.
2-Flu or o-2-(h exadecyloxym eth yl)-3-(ph en ylcar bam oyl)-
p r op a n -1-ol (22). A solution of 21 (110 mg, 0.22 mmol) and
potassium hydroxide (73 mg, 1.3 mmol) in methanol (5 mL)
was stirred at room temperature for 2 h. The mixture was
poured into water (10 mL) and extracted with diethyl ether.
The combined ethereal extract was washed with water, dried
over magnesium sulfate, and filtered through silica gel (3 cm).
After evaporation of the solvent the fluorohydrin 22 was
obtained as a white solid. Yield: 85 mg (72%). Mp 71 °C
(pentane/diethyl ether 1:1); IR: ν˜ 3420 (br), 3344 (br), 2917
and 2849 (s), 1695 (s), 1600 (m), 1555 (s), 1472 and 1451 (m),
1322 (m), 1255 (m), 1123 (m), 1086 (m), 1073 (m), 1064 (s),
758 (m); 1H NMR: δ 0.88 (t, 3J H,H ) 6.7 Hz), 1.25-1.37 (m, 26
H), 1.52-1.62 (m, 2 H, OCH2CH2), 2.30 (br s, 1 H, OH), 3.49
2′-(Tr im eth yla m m on iu m )eth yl 2-flu or o-2-(h exa d ecyl-
oxym et h yl)-3-m et h oxyp r op -1-ylp h osp h a t e (6). Analo-
gously to ref 25, a mixture of the fluorohydrin 8 (10 mg, 27
µmol) and triethylamine (12 µL, 80 µmol) in dry THF (1 mL)
was prepared in an argon-flushed, dried Schlenk vessel. A
solution of 2-chloro-2-oxo-1,3,2-dioxaphospholane (8 µL, 85
µmol) in dry THF (0.5 mL) was added to this flask at 0 °C,
and the resulting mixture was stirred at this temperature for
30 min. At the end of this time, the mixture was allowed to
warm to room temperature and stirred there for an additional
6 h. The precipitated triethylammonium chloride was filtered
through silica gel under argon (1 cm, THF as eluent), and the
solvent was evaporated in a vacuum. The residue was dis-
solved under argon in dry acetonitrile (1 mL), placed in a
pressure vessel, and cooled to -78 °C. Trimethylamine (about
0.2 mL) was condensed into the vessel, which was sealed and
heated at 60 °C for 68 h. The resulting liquid was separated
and maintained at -20 °C for 4 h. A yellowish waxy material
precipitated. This was purified by column chromatography
(chloroform/methanol/water, 65:25:4) to obtain, besides start-
ing material (3.5 mg, 35%), the desired ether lipid 6 as a
yellowish solid (5 mg, 35% yield). 1H NMR (CDCl3/CD3OD,
1:1): δ 0.89 (t, 3J H,H ) 6.6 Hz, 3 H), 1.25-1.34 (m, 26 H), 1.52-
3
(t, J H,H ) 6.7 Hz, 2 H, OCH2CH2), 3.61-3.85 (m, 4 H), 4.41
2
3
(ABX, J H,H ) 12.4 Hz, J H,F ) 18.1 Hz, 1 H), 4.48 (ABX,
2J H,H ) 12.4 Hz, 3J H,F ) 21.7 Hz, 1 H), 6.71 (s, 1 H), 7.05-7.11
(m, 1 H), 7.27-7.39 (m, 4 H); 13C NMR: δ 14.1 (q), 22.7 (t),
2
26.0 (t), 29.3 to 29.6 (11t), 31.9 (t), 62.2 (t, J C,F ) 28.0 Hz),
63.8 (t, 2J C,F ) 25.4 Hz), 70.4 (t, 2J C,F ) 25.4 Hz), 72.4 (t), 95.8
1
(ds, J C,F ) 178.0 Hz), 119.0 (d), 123.9 (d), 129.1 (d), 137.4 (s),
153.4 (s); 19F NMR: δ -175.5 (m); Mass spectrum m/z (%):
468 (2), 467 (6), 224 (2), 196 (2), 167 (2), 155 (6), 154 (3), 153
(3), 149 (3), 141 (2), 140 (2), 139 (5), 137 (5), 127 (2), 126 (4),
125 (16), 124 (3), 120 (14), 119 (100), 96 (9), 93 (22), 91 (45),
87 (21), 86 (14), 85 (23), 84 (13), 83 (37), 82 (16), 71 (37), 70
(27), 69 (41), 68 (18). Anal. Calcd for C27H46FNO4 (467.70): C,
69.34; H, 9.91; N, 3.00. Found C, 69.44; H, 9.88; N, 3.13.
3
1.61 (m, 2 H), 3.24 (s, 9 H), 3.39 (s, 3 H), 3.48 (t, J H,H ) 6.6
Hz, 2 H), 3.61-3.68 (m, 6 H), 4.02-4.10 (m, 2 H) 4.23-4.31

2084 J . Org. Chem., Vol. 66, No. 6, 2001
Burchardt et al.
(m, 2 H); 19F NMR (CDCl3/CD3OD, 1:1): δ -173.7 (ttt, 3J H,F
)
3-Ch lor oa cetoxy-2-flu or o-2-(h exa d ecyloxym eth yl)p r o-
19.1 Hz). 31P NMR (CDCl3/CD3OD, 1:1): δ 5.3 (m); Mass
spectrum, Maldi-TOF, m/z: 529 ( 0.05% [M+ + 2H].
Lipase-Catalyzed Deracemizations
p a n -1-ol (16b). Mp 53 °C (pentane/diethyl ether 3:1). 1H
3
NMR: δ 0.88 (t, J H,H ) 6.5 Hz, 3 H), 1.22-1.38 (m, 26 H),
3
1.51-1.60 (m, 2 H), 2.01 (br s, 1 H), 3.48 (t, J H,H ) 6.6 Hz, 2
(a ) Lip a se-Ca ta lyzed Hyd r olyses of (()-1,3-Dia cetoxy-
2-flu or o-2-(h exa d ecyloxym eth yl)p r op a n e (17a ). The di-
acetate 17a , dissolved in THF, was added to a phosphate buffer
(10 mL, 0.1 M, pH ) 7.0) containing the corresponding lipase
and stirred at room temperature for the time given in Table
1. The reaction was stopped by addition of a small amount of
NaCl, Celite 577 (2 g) and ethyl acetate (10 mL). The enzyme
and Celite were removed by filtration. The filtrate was
extracted with ethyl acetate. The combined organic layer was
dried over magnesium sulfate and concentrated under reduced
pressure. The crude residue was passed through a short
column (3 cm silica gel, ethyl acetate as eluent) and analyzed
by GC in order to determine the product ratio. After evapora-
tion of the solvent, the residue was separated by column
chromatography (pentane/diethyl ether, 1:1). The exact pa-
rameters of the experiments and the results are given in
Table 1.
(b) Lip a se-Ca ta lyzed Acetyla tion a n d Ch lor oa cetyla -
tion of 2-F lu or o-2-(h exa d ecyloxyeth yl)p r op a n e-1,3-d iol
(20). The diol 20 and the acyl donor were dissolved in toluene,
and the enzyme (occasionally immobilized) was added. The
mixture was stirred at room temperature for the length of time
given in Table 2. The reaction was stopped by filtration of the
mixture through a short column of silica gel (toluene as eluent).
The mixture was analyzed by GC, the solvent was evaporated,
and the residue was separated by column chromatography
(pentane/diethyl ether, 1:1). The exact parameters of the
experiments and the results are given in Table 2.
H), 3.59-3.71 (m, 2 H), 3.73-3.88 (m, 2 H), 4.10 (s, 2 H), 4.36-
4.54 (m, 2 H); 13C NMR: δ 14.1 (q), 22.6 (t), 26.0 (t), 29.3 to
2
29.7 (11t), 31.9 (t), 40.5 (t), 62.7 (dt, J C,F ) 25.4 Hz), 64.7 (dt,
2
2J C,F ) 25.4 Hz), 69.9 (dt, J C,F ) 28.0 Hz), 72.4 (t), 95.1 (ds,
1J C,F ) 178.0 Hz), 166.9 (s); 19F NMR: δ -175.9 (m); Mass
spectrum, m/z (%): 424/426 (0.5) [M+•], 310 (5), 255 (4), 225
(3), 223 (3), 201 (11), 183 (13), 167 (6), 155 (9), 149 (4), 141
(5), 125 (8), 111 (14), 99 (13), 97 (28), 87 (23), 86 (24), 85 (39),
83 (33), 71 (60), 70 (25), 69 (43). Anal. Calcd for C22H42ClFO4
(425.02): C, 62.17; H, 9.96. Found C, 62.42; H, 10.04.
Ack n ow led gm en t. This work was supported by the
Deutsche Forschungsgemeinschaft, the Fond der Che-
mischen Industrie, Germany, and the Ministry of Edu-
cation, Science, Sports and Culture, J apan. We thank
the Bayer AG, Leverkusen, Germany, and Amano
Pharmaceutical Co., Ltd., Nagoya, J apan, for kind
donation of chemicals and enzymes, respectively, and
Dr. D. Herrmann, Heidelberg Pharma Holding, GmbH
& Co KG, Germany, for biological tests.
Su p p or tin g In for m a tion Ava ila ble: Syntheses, analyti-
cal and spectroscopic data of compounds 9, 11, and 12. This
material is available free of charge via the Internet at
http://pubs.acs.org.
J O0016172