Practical syntheses of sphingosine-1-phosphate and analogues

Article abstract of DOI:10.1055/s-0028-1083373

Sphingosine-1-phosphate (S1P, 1) is a bioactive sphin- golipid metabolite involved in a variety of critical cellular processes including proliferation, survival, and migration. For this reason the stereoselective syntheses of S1P and analogues are of great interest. Based on L-serine as source of chirality we achieved practical routes to prepare S1P (1) and the aryl group containing analogues 3 and 4 in fair amounts. The crucial stages of the syntheses are: introduction of the required side chain by addition of appropriate organometal- lics to Garner's aldehyde and conversion of the primary alcohols into the corresponding phosphates. Georg Thieme Verlag Stuttgart.

Full text of DOI:10.1055/s-0028-1083373

PAPER
759
Practical Syntheses of Sphingosine-1-Phosphate and Analogues
S
ynthese
s
of Sphin
i
gosine
r
-1-Phosp
g
hate and An
i
alogue
n
ie Blot,a Ulrich Jacquemard,a Hans-Ulrich Reissig,*a Burkhard Kleuserb
a
Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany
Fax +49(30)83855367; E-mail: hans.reissig@chemie.fu-berlin.de
Institut für Pharmazie, Freie Universität Berlin, Königin-Luise Str. 2–4, 14195 Berlin, Germany
b
Received 18 July 2008; revised 13 November 2008
sphingosine. The sphingoid base sphingosine can be phos-
phorylated by sphingosine kinases to form S1P.3
Abstract: Sphingosine-1-phosphate (S1P, 1) is a bioactive sphin-
golipid metabolite involved in a variety of critical cellular processes
including proliferation, survival, and migration. For this reason the
stereoselective syntheses of S1P and analogues are of great interest.
Based on L-serine as source of chirality we achieved practical routes
to prepare S1P (1) and the aryl group containing analogues 3 and 4
in fair amounts. The crucial stages of the syntheses are: introduction
of the required side chain by addition of appropriate organometal-
lics to Garner’s aldehyde and conversion of the primary alcohols
into the corresponding phosphates.
HO
HO
O
P
O
P
HO
–O
HO
–O
O
C13H27
C13H27
+
+
NH3
NH3
1 = S1P
sphingosine-1-phosphate
2
phosphonate analogue
Key words: phosphates, amino alcohols, lipids, organometallic re-
agents, sphingosine derivatives
HO
O
HO
–O
P
C12H25
O
O
HO
+
NH3
HO
Sphingosine-1-phosphate (S1P) has been discovered as a
novel lipid mediator, which is involved in a variety of bi-
ological responses such as proliferation, migration, sur-
vival, adhesion, and differentiation. These important and
tightly regulated functions influence several biological
processes like angiogenesis, wound healing, neurogene-
sis, and immune cell regulation. The lysophospholipid
P
C10H21
3
–O
O
+
NH3
4
aromatic analogues
Figure 1 Sphingosine-1-phosphate (1) and its analogues 2, 3, and 4
signals mainly through five related G protein-coupled re-
1
ceptor (GPCR) subtypes, now designated as S1P1–5
.
Owing to the promising therapeutic potential of S1P (1),
it is a challenge to develop a practical stereoselective syn-
thesis of this compound, which should also allow a fairly
easy scale-up to gram quantities. In addition, preparation
of compound 3 containing an aromatic moiety instead of
the double bond and the new analogue 4 incorporating a
styrene unit were desirable (Figure 1). The phosphonate
analogue 24 was also of interest (Figure 1). By checking
the different literature approaches to S1P5–8 we decided to
prepare N-Boc-protected intermediates 5, 6, and 7, respec-
It has been shown that D-erythro forms (2S,3R) of S1P
have higher receptor affinities than the other stereoiso-
mers, indicating that 3D spatial orientations of key func-
tionalities, which are the C2-amino and C3-hydroxy
groups of S1P, are very important for the specific interac-
tion with the S1P1 receptor subtype. Computational mod-
elling also suggests that the aliphatic moiety of S1P may
positively interact with the hydrophobic area formed by
the receptor.2
The de novo biosynthesis of sphingolipids is initiated by tively, which should be available from Garner’s aldehyde9
condensation of L-serine and palmitoyl-CoA to form 3- 8 and a suitable organolithium compound for the introduc-
ketosphinganine, a process that is catalysed by the en- tion of the lipophilic side chain. Garner’s aldehyde 8 is
zyme serine palmitoyl transferase. The product is then re- easily accessible in five steps starting from L-serine in
duced by the enzyme 3-ketosphinganine reductase in a 69% overall yield (Scheme 1).10
NADPH-dependent manner resulting in D-erythro-sphin-
ganine. A further step in the biosynthesis is the acylation
of sphinganine to dihydroceramide by the sphinganine N-
acyltransferase. Then, a desaturation to ceramide takes
place in the presence of dihydroceramide desaturase.
Ceramide can also be released from sphingomyelin by
sphingomyelinases or deacylated by ceramidases to
Deprotonation of commercially available pentadec-1-yne
(9) with n-butyllithium and addition of the resulting carb-
anion to Garner’s aldehyde (8) furnished the expected
secondary alcohol 10 in 83% yield and acceptable diaste-
reoselectivity [(4S,1¢R)-/(4S,1¢S)-isomer = 85:15].8c The
subsequent reduction with lithium in liquid ammonia pro-
vided the expected E-configured alkene 11 with good ef-
ficacy (between 62 to 81% yield, depending on the
individual experiment).8a Removal of the acetonide unit
SYNTHESIS 2009, No. 5, pp 0759–0766
x
x
.
x
x
.2
0
0
9
was achieved under acidic conditions affording N-Boc-
protected sphingosine 5 as crucial intermediate in 87%
Advanced online publication: 11.02.2009
DOI: 10.1055/s-0028-1083373; Art ID: T11808SS
© Georg Thieme Verlag Stuttgart · New York

760
V. Blot et al.
PAPER
O
P
OH
R
and 15 were prepared in three and two steps, respectively
(Scheme 3). The Grignard reagent derived from 1-bro-
moundecane was added to 3-bromobenzaldehyde (12) to
furnish alcohol 13 in 71% yield. We were not able to fully
reproduce the literature described method11 (Me3SiCl,
NaI, acetonitrile, hexane) for selective removal of the hy-
droxy group of 13. We therefore developed modified two-
step procedures. Ionic reduction of 13 employing triethyl-
silane and boron trifluoride12,13 delivered a 93:7 mixture
of the desired compound 14 together with alkene 15
which is obviously formed from 13 by acid-induced water
elimination. Exposure of this mixture to hydrogen and
palladium on charcoal for short time (3 minutes) afforded
compound 14 and phenyldodecane 16 (ca. 5%). It was not
necessary to remove this side product since it is inert to
magnesium in the next step of the sequence. The inten-
tional synthesis of styrene derivative 15 was achieved in
quantitative yield by treatment of alcohol 13 with p-tolu-
enesulfonic acid.
HO
–O
O
+
NH3
1 R = R1
3 R = R2
4 R = R3
OH
HO
R
OH
NHBoc
O
P
5 R = R1
R1
HO
–O
6 R = R2
7 R = R3
+
NH3
2
O
NH2
CO2H
L-serine
HO
O
H
NBoc
8
R1
R2
=
=
C13H27
C12H25
OH
C11H23
O
C11H23MgBr
Br
Br
H
THF, 0 °C, 1 h
71%
12
13
R3
=
C10H21
Et3SiH, BF3⋅OEt2
PTSA
CH2Cl2, r.t., overnight
toluene
Scheme 1 Retrosynthetic analysis for target compounds 1–4
14/15 = 93:7
reflux, 8 h
14/15 = 0:100
quant
Br
C12H25
Br
yield (Scheme 2). At this stage, only one diastereomer
was observed by NMR spectroscopy. Apparently the mi-
nor diastereomer has progressively been removed during
the purification steps from 10 to 5. Thus, a very short and
fairly efficient route to prepare the sphingosine core was
achieved (8 steps from L-serine 31–40% overall yield) us-
ing this combination of known methods, which is also ap-
plicable to larger scale.
C11H23
14
Pd/C, H2
EtOH
14
r.t., 3 min
+
+
76%
(2 steps
from a mixture
of 14/15 93:7)
C12H25
Br
C10H21
16
15
Scheme 3 Synthesis of aryl bromides 14 and 15 starting from 3-bro-
mobenzaldehyde
OH
1'
n-BuLi, THF
–23 °C, 30 min
4
C13H27
O
then 8, –23 °C, 1 h
Metallation of aryl bromides 14 and 15 with n-butyllithi-
um generated the corresponding organolithium intermedi-
ates (Scheme 4). These reactions have to be performed
under strict exclusion of moisture in rigorously flame-
dried glassware; otherwise considerably lower yields
have been observed. The additions of these organolithium
species to Garner’s aldehyde 8 provided the benzylic al-
cohols 17 and 18, respectively, in approximately 70%
yield. The diastereoselectivities of these additions are
only moderate giving ratios ranging from 4:1 to 6:1. How-
ever, this disadvantage could be corrected by PCC oxida-
tion of secondary alcohols 17 and 18 to furnish ketones 19
and 20, which were then stereoselectively reduced with
diisobutylaluminum hydride. Thus, the required alcohols
17 and 18 were finally obtained with diastereoselectivities
in the range of 95:5. Cleavage of the acetonide was rou-
tinely achieved as above under acidic conditions deliver-
ing the required N-protected sphingosine analogues 6 and
7 in excellent yields. Complete deprotection occurred
83%
NBoc
C13H27
9
10
Li
NH3, THF
–70 °C
48 h
62–81%
OH
OH
LiCl,
AcOH–H2O (10:1)
O
HO
C13H27
C13H27
r.t., 14 h
87%
NBoc
11
NHBoc
5
Scheme 2 Synthesis of N-Boc-protected sphingosine 5
Syntheses of compounds containing the aryl units were
achieved following essentially the protocol of Bittman et
al.11 as depicted in Scheme 4. First, styrene derivatives 14
Synthesis 2009, No. 5, 759–766 © Thieme Stuttgart · New York

PAPER
Syntheses of Sphingosine-1-Phosphate and Analogues
761
with trifluoroacetic acid at room temperature to afford also be applicable to the preparation of phosphonate ana-
sphingosine analogues 2111 and 22 in 89 and 97% yield, logues incorporating the aryl moiety.
respectively.
OH
O
OH
P(OMe)3, CBr4
MeO
MeO
OH
P
O
R
n-BuLi, THF
–45 °C, 1 h
HO
R
pyridine,
0 °C to r.t., 3 h
R
Br
R
NHBoc
O
NHBoc
NBoc
then 8
5 R = R1
23 R = R1, 61–77%
24 R = R2, 67%
25 R = R3, 76%
–45 °C, 1 h
6 R = R2
7 R = R3
14 R = R1 = C12H25
17 R = R1, 60–76%, dr 78:22
18 R = R2, 74%, dr 86:14
15 R = R2 = CH=CHC10H21
PCC
CH2Cl2, r.t.
overnight
TMSBr, CH2Cl2, r.t., 1 h
then MeOH, r.t., 1 h
OH
R
O
HO
–O
P
O
+
NH3
O
OH
1 R = R1, 53%
DIBAL-H
R
R
O
3 R = R2, 32%
4 R = R3, 59%
O
toluene
r.t., 30 min
NBoc
NBoc
17 R = R1, 96%, dr 93:7
18 R = R2, 93%, dr 95:5
19 R = R1, 79%
20 R = R2, 80%
R1
=
R2
C10H21
=
C12H25
C13H27
R3 =
LiCl,
AcOH–H2O
(10:1)
overnight, r.t.
Scheme 5 Deprotection of 5, 6, and 7 leading to S1P 1 and its ana-
logues 3 and 4
OH
OH
TFA, CH2Cl2
r.t., 2 h
By combining and optimizing literature known proce-
dures for the synthesis of sphingosine phosphate 1 and its
analogues 3 and 4 we could make available these biologi-
cally active compounds in fair amounts. The developed
sequence was suitable to prepare multi-gram quantities of
S1P (1).17 Furthermore, we considerably improved the ap-
proach to analogue 3 and thereby established also a syn-
thesis of the new compound 4. Development of new
analogues of S1P following these methods as well as eval-
uation of their biological properties will be reported in due
course.
R
R
HO
HO
NH2
BocHN
6 R = R1, 87%
7 R = R2, 88%
21 R = R1, 89%
22 R = R2, 97%
Scheme 4 Synthesis of sphingosine analogues 21 and 22 and their
N-Boc-protected derivatives 6 and 7
N-Boc-protected sphingosine 5 and its aryl analogues 6
and 7 were then converted into the required phosphates
1,14 3,2 and 4 (Scheme 5). For this purpose the primary hy-
droxy group of 5, 6, or 7 was transformed into the corre-
sponding phosphoric acid triesters 23, 24, and 25
employing trimethyl phosphite, tetrabromomethane, and
pyridine.15 This method worked reliably with these sub-
strates and provided the products in yields ranging from
60 to almost 80% and a diastereomeric purity of >95:5 as
All reactions were performed under argon in flame-dried flasks, and
the components were added by means of syringes. All solvents were
dried by standard methods. TLC analyses were carried out on com-
mercial Polygram Sil G/UV254. Column chromatography was per-
formed using 70–230 mesh silica gel (Merck). Unless stated
otherwise, 1H and 13C NMR spectra were recorded on Bruker (AM-
270, DRX-500) or Jeol spectrometer (Eclipse 500). For the 1H NMR
and 13C NMR spectra, the chemical shifts are related to TMS or to
the CDCl3 signal (dH = 7.26, dC = 77.0). For 31P NMR, H3PO4 (85%
in H2O, dP = 0.00) was used as an external reference and the spectra
were 1H decoupled. IR spectra were measured on Nicolet spectrom-
eter FTIR 5 SXC. MS and HRMS analyses were performed on
Finnigan MAT 711 (EI, 80 eV, 8 kV), MAT CH7A (EI, 80 eV, 3
1
determined by H NMR spectroscopy. Complete depro-
tection of these intermediates was successfully performed
by trimethylsilyl bromide treatment and subsequent disso-
lution in methanol, which efficiently furnished the re-
quired ammonium phosphates 1, 3, and 4 as colourless
solids. Although all by-products are volatile the target
compounds have to be carefully purified by recrystallisa-
tion in THF–H2O (2:1), which will result in the loss of
some material, and thus may explain the moderate yield
for the final step of the sequence.
kV), and CH5DF (FAB, 80 eV,
3 kV, CH2Cl2–MNBA;
MNBA = m-nitrobenzyl alcohol) instruments. Melting points were
determined with a Reichert apparatus and are not corrected. Optical
rotations ([a]D) were determined with Perkin-Elmer 241 polarime-
ters. Analytical HPLC was performed on a Merck Hitachi LaChrom
HPLC system using a RP 18 Kromasil column. The components
were eluted with a gradient of MeOH and 0.07 M aq K2HPO4 solu-
tion. Garner’s aldehyde 8 was prepared according to literature pro-
cedures.10
Following the protocol of Schmidt et al.,4 N-Boc-protect-
ed sphingosine 5 was converted into phosphonate 216 in
six steps with ca. 15% overall yield. This sequence should
Synthesis 2009, No. 5, 759–766 © Thieme Stuttgart · New York

762
V. Blot et al.
PAPER
tert-Butyl (4S,1¢R)-4-(1¢-Hydroxyhexadec-2¢-ynyl)-2,2-dimeth-
yl-3-oxazolinecarboxylate (10)8c
The reaction mixture was stirred overnight at r.t., then concentrated
and co-evaporated with hexane (2 × 10 mL). The residue was puri-
fied by chromatography on silica gel (hexane–EtOAc, 1:1) to afford
5 (1.25 g, 87%) as colourless solid; mp 58–61 °C (Lit.8a mp 58–
60 °C). The specific optical rotation of 5 was not determined since
the literature values were fairly low and [a]D ranged from –2.34 (c
0.88, CHCl3)6c to +2.40 (c 1.00, CHCl3).4
To a solution of pentadec-1-yne (9) (6.50 g, 31.2 mmol) in THF
(280 mL) at –23 °C was added n-BuLi (2.5 M in hexanes, 14 mL,
35.0 mmol). After 30 min, a solution of 8 (5.30 g, 23.1 mmol) in
THF (150 mL) at –23 °C was added via a syringe. The colourless
solution was stirred for 1 h, then it was quenched with aq sat. NH4Cl
solution (150 mL). The aqueous phase was extracted with CH2Cl2
(3 × 100 mL), the combined organic phases were washed with brine
(200 mL), dried (MgSO4), and concentrated. Purification by chro-
matography on silica gel (hexane–EtOAc, 9:1) gave alcohol 10
(8.40 g, 83%) as mixture of two diastereomers (ratio: ca. 85:15) as
a yellow oil. The (4S,1¢R)-product was obtained as major isomer
while the minor (4S,1¢S)-product was removed during the following
steps.
IR (KBr): 3350 (O–H), 2955–2850 (C–H), 1690 (C=O), 1530,
1465, 1365, 1250, 1175, 1085 cm–1.
1H NMR (500 MHz, CDCl3): d = 0.86 (t, J = 7.0 Hz, 3 H, CH3),
1.08–1.43 (m, 22 H, 11 CH2), 1.44 [s, 9 H, C(CH3)3], 2.04 (q, J = 7.1
Hz, 2 H, CH2), 2.75 (br s, 1 H, OH), 3.58 (br s, 1 H, 2-H), 3.69 and
3.92 (AB part of ABX system, JAX = JBX = 3.6 Hz, JAB = 11.3 Hz, 2
H, 1-H), 4.28–4.32 (m, 1 H, 3-H), 5.30 (d, J = 7.7 Hz, 1 H, NH),
5.51 (tdd, J = 1.0, 6.4, 15.3 Hz, 1 H, 4-H), 5.76 (dtd, J = 1.2, 7.1,
15.3 Hz, 1 H, 5-H).
13C NMR (125.8 MHz, CDCl3): d = 14.0 (q, CH3), 22.6 (t, CH2),
28.3 [q, C(CH3)3], 29.1, 29.2, 29.3, 29.4, 29.5, 29.67, 29.70, 29.74*,
31.8, 32.2 (10 t, CH2), 55.4 (d, C-2), 62.3 (t, C-1), 74.1 (d, C-3),
79.6 [s, C(CH3)3], 129.0, 134.1 (2 d, C-4, C-5), 156.4 (s, C=O). * 2
C atoms.
(4S,1¢R)-Diastereomer
IR (KBr): 3450 (O–H), 2975–2855 (C–H), 1705, 1675 (C=O),
1455, 1390, 1365, 1260, 1175, 1085 cm–1.
1H NMR (500 MHz, CDCl3): d = 0.85 (t, J = 6.9 Hz, 3 H, CH3),
1.26–1.64 (m, 37 H, 11 CH2, 5 CH3), 2.15 (dt, J = 1.7, 7.0 Hz, 2 H,
CH2), 3.85 (mc, 1 H, 5-H), 3.98–4.03 (m, 2 H, 5-H, 4-H), 4.51 (br s,
1 H, 1¢-H), 4.72 (br s, 1 H, OH).
The NMR data fit with the values given in ref. 8a.
13C NMR (125.8 MHz, CDCl3): d = 14.0 (q, CH3), 18.7, 22.6 (2 t,
CH2), 25.3, 25.7 [2 q, C(CH3)2], 28.3 [q, C(CH3)3], 28.4, 28.8, 29.0,
29.3, 29.4, 29.67, 29.68, 29.69, 29.72, 31.8 (10 t, CH2), 62.7, 63.9
(2 d, C-1¢, C-4), 65.0 (t, C-5), 77.6, 81.0, 86.9 [3 s, C(CH3)3, C-2¢,
C-3¢], 94.8 [s, C(CH3)2], 153.8 (s, C=O).
MS [FAB (+), MNBA–CH2Cl2]: m/z (%) = 398 (5, [M – H]+), 324
(100, [M – C4H9 – H2O]+), 282 (6, [M – NHBoc]+).
1-(3-Bromophenyl)dodecan-1-ol (13)11
To a suspension of Mg turnings (0.30 g, 1.30 mmol) in THF (16
mL) was added a solution of 1-bromoundecane (3.00 g, 1.30 mmol)
in THF (12 mL) at r.t. After almost complete dissolution of the met-
al (2 h), the mixture was cooled to 0 °C and a solution of 3-bromo-
benzaldehyde (12; 2.00 g, 1.00 mmol) in THF (22 mL) was slowly
added. The reaction mixture was stirred at this temperature for 1 h
and quenched with cold aq 1 M HCl solution (20 mL). The aqueous
layer was extracted with Et2O (3 × 20 mL). The combined organic
layers were washed with brine (20 mL), dried (MgSO4), and con-
centrated. Chromatography of the residue on silica gel (hexane–
EtOAc, 9:1) afforded the aromatic alcohol 13 (2.63 g, 71%) as a
low-melting colourless solid; mp 28–31 °C.
MS [FAB (+), MNBA–CH2Cl2]: m/z (%) = 459 (5, [M + Na]+), 437
(3, [M]+), 382 (13), 365 (11), 100 (24), 57 (100, [C4H9]+).
Separated NMR signal of (4S,1¢S)-diastereomer:
1H NMR (500 Hz, CDCl3): d = 4.63 (br s, 1 H, 1¢-H).
tert-Butyl (4S,1¢R,2¢E)-4-(1¢-Hydroxyhexadec-2¢-enyl)-2,2-di-
methyl-3-oxazolinecarboxylate (11)8a
To a solution of ammonia (140 mL), condensed at –70 °C, was add-
ed Li (2.10 g, 14.6 mmol) in portions. After dissolution of the metal,
a solution of 10 (2.20 g, 5.00 mmol) in THF (140 mL) was added
dropwise. The resulting blue solution was stirred at –70 °C for 48 h,
then quenched with solid NH4Cl (60 g). After evaporation of the
ammonia at r.t., the reaction mixture was diluted with a mixture of
THF–H2O (1:1, 200 mL) and extracted with EtOAc (3 × 150 mL).
The combined organic layers were dried (MgSO4) and concentrat-
ed. Chromatography of the residue on silica gel (hexane–EtOAc,
8:2) gave alcohol 11 (1.80 g, 81%) as a colourless oil.
IR (KBr): 3340 (O–H), 3060 (=C–H), 2955–2855 (C–H), 1595,
1570, 1465, 1070, 780, 700 cm–1.
1H NMR (500 MHz, CDCl3): d = 0.88 (t, J = 7.3 Hz, 3 H, CH3),
1.18–1.45 (m, 18 H, 9 CH2), 1.61–1.83 (m, 2 H, CH2), 2.17 (s, 1 H,
OH), 4.60 (t, J = 6.5 Hz, 1 H, 1-H), 7.18 (t, J = 7.7 Hz, 1 H, 5¢-H),
7.23 (td, J = 1.6, 7.7 Hz, 1 H, 6¢-H), 7.38 (dt, J = 1.6, 7.7 Hz, 1 H,
4¢-H), 7.48 (t, J = 1.6 Hz, 1 H, 2¢-H).
13C NMR (125.8 MHz, CDCl3): d = 14.1 (q, CH3), 22.7, 25.6, 29.3,
29.4, 29.5, 29.6, 29.7, 29.9, 31.9, 39.1 (10 t, CH2), 73.9 (d, C-1),
122.5 (s, C-1¢), 124.5, 129.0, 129.9, 130.4 (4 d, Ar), 147.3 (s, C-3¢).
IR (KBr): 3440 (O–H), 2975–2855 (C–H), 1700, 1675 (C=O),
1465, 1455, 1390, 1365, 1255, 1175 cm–1.
1H NMR (500 MHz, CDCl3): d (major diastereomer) = 0.82 (t,
J = 6.9 Hz, 3 H, CH3), 1.09–1.61 (m, 37 H, 11 CH2, 5 CH3), 1.98 (q,
J = 7.1 Hz, 2 H, CH2), 3.65–4.32 (m, 4 H, 5-H, 4-H, 1¢-H), 5.39 (dd,
J = 5.6, 15.1 Hz, 1 H, 2¢-H), 5.67 (dt, J = 7.1, 15.1 Hz, 1 H, 3¢-H).
13C NMR (125.8 MHz, CDCl3): d (major diastereomer) = 14.0 (q,
CH3), 22.7 (t, CH2), 24.7, 26.3 [2 q, C(CH3)2], 28.4 [q, C(CH3)3],
29.2, 29.3, 29.4, 29.5, 29.6, 29.67, 29.69, 29.70, 29.71, 31.8, 32.4
(11 t, CH2), 62.2 (d, C-4), 65.0 (t, C-5), 73.8 (d, C-1¢), 80.8 [s,
C(CH3)3], 94.3 [s, C(CH3)2], 128.2, 133.1 (2 d, C-2¢, C-3¢), 153.9 (s,
C=O).
The spectroscopic data fit with the values given in ref. 11.
MS (EI, 80 eV, 90 °C): m/z (%) = 340 (5, [M]+), 261 (2, [M – Br]+),
185 (100, [M – C11H23]+).
1-Bromo-3-dodecylbenzene (14)
To a solution of alcohol 13 (1.10 g, 3.22 mmol) in CH2Cl2 (22 mL)
at 0 °C were added Et3SiH (0.78 mL, 4.83 mmol) and BF3⋅OEt2
(0.61 mL, 4.83 mmol). The reaction mixture was slowly warmed to
r.t. and stirred overnight. The resulting solution was quenched with
H2O (15 mL) and the aqueous phase extracted with CH2Cl2 (3 × 15
mL). The combined organic layers were washed with brine (15
mL), dried (MgSO4), and concentrated. The residue was filtered
through silica gel (hexane) to obtain a mixture of products 14 and
15 (1.05 g, 14:15 = 93:7) as a pale yellow oil. To a suspension of Pd/
C (11 mg) in EtOH (5 mL, pretreated by bubbling H2 for 1 h) at r.t.
MS (EI, 80 eV, 130 °C): m/z (%) = 439 (0.4, [M]+), 366 (<1, [M –
C4H9O]+), 100 (72), 57 (100, [C4H9]+).
(2S,3R,4E)-2-(tert-Butoxycarbonylamino)octadec-4-ene-1,3-
diol (N-Boc-sphingosine, 5)
To a solution of alcohol 11 (1.58 g, 3.60 mmol) in a mixture of
AcOH–H2O (10:1, 11 mL) was added LiCl (0.32 g, 7.20 mmol).
Synthesis 2009, No. 5, 759–766 © Thieme Stuttgart · New York

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Syntheses of Sphingosine-1-Phosphate and Analogues
763
was added a solution of the mixture 14 and 15 (230 mg, 0.71 mmol)
in EtOH (2 mL). The mixture was stirred for 3 min and immediately
filtered through a pad of Celite, washed with Et2O (50 mL), and the
filtrate was concentrated. The residue was filtered through silica gel
(hexane) to afford 14 (219 mg, 76% over 2 steps) as colourless oil,
which contained side product 16 in small amount (ca. 5%).
J = 7.6 Hz, 1 H, 5¢¢-H), 7.28 (d, J = 7.6 Hz, 1 H, Ar), 7.48 (s, 1 H,
2¢¢-H).
The ratio of (4S,1¢R)-isomer/(4S,1¢S)-isomer was determined by 1H
NMR (500 MHz, C6D6 at 60 °C): d [(4S,1¢S)-isomer] = 4.94–4.96
(m, 1¢-H); d [(4S,1¢R)-isomer] = 5.12–5.17 (m, 1¢-H).
MS (EI, 80 eV, 130 °C): m/z (%) = 475 (2, [M]+), 275 (13, [M –
C10H18NO3]+), 200 (35, [C10H18NO3]+), 144 (30), 100 (83), 57 (100,
[C4H9]+).
IR (KBr): 3060 (=C–H), 2950–2855 (C–H), 1595, 1570, 1470,
1070, 780 cm–1.
1H NMR (500 MHz, CDCl3): d = 0.89 (t, J = 7.1 Hz, 3 H, CH3),
1.21–1.48 (m, 18 H, 9 CH2), 1.56–1.63 (m, 2 H, CH2), 2.57 (t,
J = 7.9 Hz, 2 H, CH2), 7.09 (td, J = 1.6, 7.7 Hz, 1 H, 4-H), 7.13 (t,
J = 7.7 Hz, 1 H, 5-H), 7.31 (td, J = 1.6, 7.7 Hz, 1 H, 6-H), 7.33 (t,
J = 1.6 Hz, 1 H, 2-H).
13C NMR (125.8 MHz, CDCl3): d = 14.1 (q, CH3), 22.7, 29.2, 29.3,
29.4, 29.5, 29.6, 29.7, 31.9, 35.6 (9 t, CH2), 122.3 (s, C-1), 127.3,
128.7, 129.7, 131.4 (4 d, Ar), 145.3 (s, C-3).
tert-Butyl (4S,1¢R)-4-[1-(3-(Dodec-1-enylphenyl)hydroxymeth-
yl]-2,2-dimethyl-3-oxazolinecarboxylate (18)11
According to the procedure described for compound 17, a mixture
of 15 (1.72 g, 5.33 mmol) and n-BuLi (2.5 M in in hexanes, 2.30
mL, 5.74 mmol) in THF (46 mL) was stirred at –45 °C for 5 min.
Then a solution of 8 (940 mg, 4.10 mmol) in THF (21 mL) was add-
ed and stirred for 1 h. After workup and purification on silica gel
(hexane–EtOAc, 9:1) alcohol 18 was obtained (1.44 g, 74%, dr
86:14) as a pale yellow oil.
The NMR data fit with the values given in ref. 11.
MS (EI, 80 eV, 40 °C): m/z (%) = 324 (48, [M]+), 261 (99, [M –
IR (KBr): 3460 (O–H), 3060, 3010 (=C–H), 2975–2855 (C–H),
1700, 1455, 1380, 1255, 1175, 1100, 1070 cm–1.
C11H23]+), 91 (100, [M – Br – C11H23]+).
1H NMR (500 MHz, C6D6 at 60 °C): d = 0.89 (t, J = 6.9 Hz, 3 H,
CH3), 1.28–1.41 (m, 31 H, 8 CH2, 5 CH3), 2.13 (q, J = 7.0 Hz, 2 H,
CH2), 3.51 (t, J = 7.0 Hz, 1 H), 3.97 (br s, 1 H), 4.15 (br s, 1 H), 5.09
(mc, 1 H), 6.15–6.24 (m, 1 H, =CH), 6.40 (d, J = 15.8 Hz, 1
H, =CH), 7.13–7.26 (m, 3 H, Ar), 7.53 (s, 1 H, Ar).
The ratio of (4S,1¢R)-isomer/(4S,1¢S)-isomer was determined by 1H
NMR (500 MHz, C6D6 at 60 °C): d [(4S,1¢S)-isomer] = 4.94 (s, 1¢-
H); d [(4S,1¢R)-isomer] = 5.09 (mc, 1¢-H).
1-Bromo-3-(dodec-1-enyl)benzene (15)
To a solution of alcohol 13 (220 mg, 0.64 mmol) in toluene (7.3 mL)
was added PTSA (18 mg, 0.1 mmol). The mixture was stirred under
reflux for 8 h, then diluted with EtOAc (7.3 mL), and washed with
H2O (3 × 7 mL) and brine (3 × 7 mL). The combined organic layers
were dried (MgSO4), filtered, and then evaporated under reduced
pressure to give an oil. The crude product was purified by column
chromatography on silica gel (hexane) to afford 15 (208 mg, quant)
as a colourless oil.
MS (EI, 80 eV, 120 °C): m/z (%) = 473 (2, [M]+), 416 [M – C4H9]+,
388 [M – C4H9CO]+, 273 (13, [M – C10H18NO3]+), 200 (35,
[C10H18NO3]+), 144 (30), 100 (83), 57 (100, [C4H9]+).
IR (KBr): 3060, 3020 (=C–H), 2955–2855 (C–H), 1590, 1560,
1480, 1470, 1070, 960 cm–1.
1H NMR (500 MHz, CDCl3): d = 0.88 (t, J = 6.9 Hz, 3 H, CH3),
1.26–1.30 (m, 16 H, 8 CH2), 1.42–1.48 (m, 2 H, CH2), 2.19 (q,
J = 6.9 Hz, 2 H, CH2), 6.19–6.30 (m, 2 H, =CH), 7.14 (t, J = 7.8 Hz,
1 H, 5-H), 7.23 (td, J = 1.6, 7.8 Hz, 1 H, 4-H), 7.30 (td, J = 1.6, 7.8
Hz, 1 H, 6-H), 7.48 (t, J = 1.6 Hz, 1 H, 2-H).
HRMS (EI, 80 eV, 100 °C): m/z calcd for C29H47NO4: 473.35049;
found: 473.35133.
tert-Butyl (4S,1¢R)-4-(3-Dodecylbenzoyl)-2,2-dimethyl-3-oxazo-
linecarboxylate (19)11
To a solution of 17 (490 mg, 1.03 mmol) in CH2Cl2 (18 mL) at r.t.
was added PCC (445 mg, 2.06 mmol). The mixture was stirred
overnight and then filtered through silica gel (CH2Cl2). Ketone 19
(384 mg, 79%) was obtained as a colourless solid; mp 57–58 °C
(Lit.11 mp 60–61 °C); [a]D –43 (c 1.03, CHCl3) {Lit.11 [a]D –42 (c
3.10, CHCl3)}.
13C NMR (125.8 MHz, CDCl3): d = 14.1 (q, CH3), 22.7, 29.2, 29.3,
29.6, 29.7*, 31.9, 33.0 (7 t, CH2), 121.5 (s, C-3), 124.6 (d, Ar),
128.3 (d, =CH), 128.7, 129.5, 129.9 (3 d, Ar), 132.9 (d, =CH),
140.1 (s, C-1). * Signal with higher intensity.
MS (EI, 80 eV, 50 °C): m/z (%) = 322 (39, [M]+), 195 (9, [M –
C9H19]+), 182 (100, [M – C10H21]+), 116 (85, [M – Br – C9H19]+).
IR (KBr): 3065, 3040 (=C–H), 2975–2850 (C–H), 1715, 1670
(C=O), 1470, 1390, 1240, 1165, 1090 cm–1.
HRMS (EI, 80 eV, 50 °C): m/z calcd for C18H27Br: 322.12961;
found: 322.12900.
1H NMR (500 MHz, CDCl3): d = 0.90 (t, J = 6.9 Hz, 3 H, CH3),
1.18–1.49 (m, 29 H, 10 CH2, 3 CH3), 1.55, 1.59 (2 s, 3 H, CH3),
1.72, 1.76 (2 s, 3 H, CH3), 2.58–2.68 (m, 2 H, CH2), 3.91, 3.94 (2
dd, J = 3.7, 9.1 Hz and J = 2.8, 9.2 Hz, 1 H, 5-H), 4.25–4.36 (m, 1
H, 5-H), 5.35 (dd, J = 3.7, 7.7 Hz, 0.56 H, 4-H), 5.46 (dd, J = 2.8,
7.5 Hz, 0.44 H, 4-H), 7.32–7.45 (m, 2 H, Ar), 7.64–7.77 (m, 2 H,
Ar); due to the existence of rotamers some signals appear twice.
13C NMR (125.8 MHz, CDCl3): d = 14.1 (q, CH3), 22.7 (t, CH2),
24.7, 24.9, 25.5, 25.9 [4 q, C(CH3)2], 28.2, 28.4 [2 q, C(CH3)3],
29.27, 29.31, 29.4, 29.5, 29.62, 29.69, 29.70, 29.72, 31.4, 31.9, 35.8
(11 t, CH2), 61.6, 61.9 (2 d, C-4), 65.7, 66.1 (2 t, C-5), 80.2, 80.6 [2
s, C(CH3)3], 94.5, 95.2 [2 s, C(CH3)2], 125.5, 125.6, 128.1, 128.4,
128.4, 128.6, 133.6, 133.7 (8 d, Ar), 135.8, 135.9, 143.6, 143.8 (4 s,
Ar), 151.2, 152.2, 195.2, 196.2 (4 s, C=O); due to the existence of
rotamers most of the signals appear twice.
tert-Butyl (4S,1¢R)-4-[1-(3-Dodecylphenyl)hydroxymethyl]-2,2-
dimethyl-3-oxazolinecarboxylate (17)11
In a flame-dried flask, a solution of 14 (820 mg, 2.52 mmol) in THF
(20 mL) at –45 °C was treated with n-BuLi (2.5 M in hexanes, 1.10
mL, 2.75 mmol). The mixture was stirred for 1 h, then a solution of
8 (445 mg, 1.94 mmol, 1 equiv) in THF (12 mL) was added at this
temperature. After 1 h, the mixture was quenched by the addition of
aq sat. NH4Cl solution (30 mL). The aqueous layer was extracted
with Et2O (3 × 30 mL) and the combined organic phases were
washed with brine (30 mL), dried (MgSO4), and concentrated.
Chromatography of the residue on silica gel (hexane–EtOAc, 9:1)
gave 17 (695 mg, 75%, dr 78:22) as a pale yellow oil.
IR (KBr): 3435 (O–H), 3055 (=C–H), 2975–2855 (C–H), 1700,
1670 (C=O), 1460, 1390, 1380, 1370, 1260, 1175, 1100, 1070 cm–1.
1H NMR (500 MHz, C6D6 at 60 °C): d = 0.91 (t, J = 6.9 Hz, 3 H,
CH3), 1.24–1.65 (m, 35 H, 5 CH3, 10 CH2), 2.57 (t, J = 7.6 Hz, 2 H,
CH2), 3.51 (t, J = 7.8 Hz, 1 H), 3.97 (br s, 1 H), 4.15 (br s, 1 H),
5.12–5.17 (m, 1 H, 1¢-H), 7.02 (d, J = 7.6 Hz, 1 H, Ar), 7.18 (t,
MS (EI, 80 eV, 110 °C): m/z (%) = 473 (<1, [M]+), 458 (1, [M –
Me]+), 358 (11), 273 (37, [M
–
C10H18NO3]+), 200 (51,
[C10H18NO3]+), 100 (100), 57 (51, [C4H9]+).
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V. Blot et al.
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tert-Butyl (4S,1¢R)-4-(3-Dodec-1-enylbenzoyl)-2,2-dimethyl-3-
oxazolinecarboxylate (20)11
13C NMR (125.8 MHz, CDCl3): d = 14.1 (q, CH3), 22.6 (t, CH2),
28.3 [q, C(CH3)3], 29.4, 29.5, 29.6, 29.69, 29.72, 29.76, 29.77, 31.5,
31.9, 35.3 (10 t, CH2), 56.3 (d, C-2), 61.9 (t, C-1), 76.2 (d, C-3),
79.8 [s, C(CH3)3], 123.0, 125.8, 127.2, 128.3 (4 d, Ar), 140.9, 143.2
(2 s, Ar), 156.1 (s, C=O).
According to the procedure described for synthesis of 19, a mixture
of 18 (1.02 g, 2.16 mmol) and PCC (930 mg, 4.31 mmol) in CH2Cl2
(48 mL) was stirred overnight at r.t. After filtration through silica
gel (CH2Cl2), 20 (884 mg, 80%) was obtained as a colourless solid;
mp 54 °C; [a]D –40.3 (c 0.27, CHCl3).
MS (EI, 80 eV, 140 °C): m/z (%) = 417 (<1, [M – H2O]+), 275 (100,
[C19H31O]+), 57 (67, [C4H9]+).
IR (KBr): 3095, 3060 (=C–H), 2970–2855 (C–H), 1710, 1695
(C=O), 1470, 1390, 1255, 1180, 1100 cm–1.
(2S,3R)-2-(tert-Butoxycarbonylamino)-3-(3-dodec-1-enylphe-
nyl)propane-1,3-diol (7)
1H NMR (500 MHz, CDCl3): d = 0.88 (t, J = 6.9 Hz, 3 H, CH3),
1.27–1.50 (m, 25 H, 8 CH2, 3 CH3), 1.57, 1.61 (2 s, 3 H, CH3), 1.74,
1.77 (2 s, 3 H, CH3), 2.19–2.25 (m, 2 H, CH2), 3.93, 3.95 (2 dd,
J = 3.5, 9.1 Hz and J = 2.9, 9.2 Hz, 1 H, 5-H), 4.29–4.33 (m, 1 H,
5-H), 5.37 (dd, J = 3.6, 7.5 Hz, 0.56 H, 4-H), 5.48 (dd, J = 2.9, 7.5
Hz, 0.44 H, 4-H), 6.26–6.43 (m, 2 H, =CH), 7.35–7.42 (m, 1 H, Ar),
7.52, 7.57 (2 d, J = 7.8 Hz, 1 H, Ar), 7.71 (t, J = 7.8 Hz, 1 H, Ar),
7.88–7.90 (2 s, 1 H, Ar); due to the existence of rotamers most of
the signals appear twice.
13C NMR (125.8 MHz, CDCl3): d = 14.2 (q, CH3), 22.8 (t, CH2),
24.7, 24.9, 25.5, 26.0, 28.3, 28.5 [6 q, C(CH3)3, C(CH3)2], 29.3,
29.3, 29.4, 29.6, 29.7, 29.7, 32.0, 33.1, 33.1 (9 t, CH2), 61.8, 62.0 (2
d, C-4), 65.8, 66.2 (2 t, C-5), 80.3, 80.8 [2 s, C(CH3)3], 94.7, 95.3 [2
s, C(CH3)2], 125.7, 125.9, 126.4, 126.7, 128.7, 128.8, 128.9, 129.0
(8 d, Ar), 130.9, 133.1, 133.4 (3 d, =CH), 135.5, 138.8, 138.9 (3 s,
Ar), 151.4, 195.4, 196.1 (3 s, C=O); due to the existence of rotamers
most of the signals appear twice.
According to the procedure described for synthesis of 5, treatment
of alcohol 18 (240 mg, 0.51 mmol) with a mixture of AcOH–H2O
(10:1, 1.67 mL) with LiCl (43 mg, 1.01 mmol) and purification by
chromatography on silica gel (hexane–EtOAc, 1:1) gave 7 (193 mg,
88%) as a colourless solid; mp 84 °C; [a]D –2.3 (c 0.13, CHCl3).
IR (KBr): 3345 (O–H), 3060, 3015 (=C–H), 2980–2850 (C–H),
1685 (C=O), 1535, 1465, 1370, 1310, 1250, 1180, 1010 cm–1.
1H NMR (500 MHz, CDCl3): d = 0.88 (t, J = 6.3 Hz, 3 H, CH3),
1.27–1.45 [m, 25 H, 8 CH2, C(CH3)3], 2.19 (t, J = 6.7 Hz, 2 H, CH2),
3.57 (d, J = 7.8 Hz, 1 H, 1-H), 3.76–3.88 (m, 2 H, 1-H, 2-H), 4.97
(br s, 1 H, 3-H), 5.49 (br s, 1 H, NH), 6.20–6.26 (m, 1 H, =CH), 6.35
(d, J = 16 Hz, 1 H, =CH), 7.20–7.32 (m, 4 H, Ar).
13C NMR (125.8 MHz, CDCl3): d = 14.2 (q, CH3), 22.8 (t, CH2),
28.4 [q, C(CH3)3], 29.38, 29.44, 29.6, 29.73, 29.74*, 32.0, 33.1 (7 t,
CH2), 56.4 (d, C-2), 62.0 (t, C-1), 76.0 (d, C-3), 79.9 [s, C(CH3)3],
123.5, 124.3, 125.3, 128.7 (4 d, Ar), 129.5, 131.8 (2 d, =CH), 138.2,
141.3 (2 s, Ar), 156.3 (s, C=O). * Signal with higher intensity.
MS (EI, 80 eV, 110 °C): m/z (%) = 471 (0.23, [M]+), 456 (1, [M –
CH3]+), 356 (11), 271 (37, [M – C10H18NO3]+), 200 (51,
[C10H18NO3]+), 100 (100), 57 (51, [C4H9]+).
MS (EI, 80 eV, >200 °C): m/z (%) = 433 (<1, [M]+), 417 (<1, [M –
H2O]+), 273 (100, [C19H29O]+), (60, [C2H5NO]+), 57 (67, [C4H9]+).
HRMS (EI, 80 eV, 140 °C): m/z calcd for C29H45NO4: 471.33487;
found: 471.33511.
HRMS (EI, 80 eV, >200 °C): m/z calcd for C26H43NO4: 433.31921;
found: 433.31866.
DIBAL-H Reduction of Ketone 1911
(2S,3R)-2-Amino-3-(3-dodecylphenyl)propane-1,3-diol (21)
To a solution of 6 (160 mg, 0.37 mmol) in CH2Cl2 (8 mL) was added
TFA (408 mL, 5.49 mmol) at r.t. After 2 h, the mixture was concen-
trated to afford crude 21, which was dissolved in CH2Cl2 (10 mL)
and washed with H2O (10 mL). The solvent was removed and the
product was purified by column chromatography on silca gel
(CH2Cl2–MeOH, 8:2) to afford 21 (110 mg, 89%) as a colourless
solid; mp 48 °C (Lit.11 mp 55.2–56.2 °C); [a]D –9.5 (c 0.30, MeOH)
{Lit.11 [a]D –22.0 (c 3.4, CHCl3).
To a solution of 19 (380 mg, 0.80 mmol) in THF (40 mL) at 0 °C
was added DIBAL-H (1.2 M in toluene, 2.5 mL 3.00 mmol). After
30 min at 0 °C, the mixture was quenched by slow addition of
MeOH (2 mL), followed by cold aq 1 N HCl solution (10 mL). The
aqueous layer was extracted with Et2O (3 × 20 mL) and the com-
bined organic layers were washed with brine (20 mL), dried
(MgSO4), and concentrated. The crude product was purified by
chromatography on silica gel (hexane–EtOAc, 8:2) to afford 17
(369 mg, 96%, dr 93:7) as a colourless oil.
IR (KBr): 3355 (O–H), 2965–2675 (=CH, C–H), 1675, 1440, 1380,
1210, 1035, 960 cm–1.
DIBAL-H Reduction of Ketone 2011
1H NMR (500 MHz, CD3OD): d = 0.90 (t, J = 6.8 Hz, 3 H, CH3),
1.29–1.34 (m, 18 H, 9 CH2), 1.61–1.64 (m, 2 H, CH2), 2.62 (t,
J = 7.3 Hz, 2 H, CH2), 3.22 (br s, 1 H, CH), 3.61 (br s, 2 H, 1-H),
4.82 (br s, 1 H, CH), 7.12 (d, J = 7.4 Hz, 1 H, Ar), 7.20–7.23 (m, 2
H, Ar), 7.28 (t, J = 7.6 Hz, 1 H, Ar).
According to the procedure described above, treatment of 20 (1.06
g, 2.25 mmol) in THF (107 mL) with DIBAL-H (1.2 M in toluene,
8.0 mL, 9.60 mmol) at 0 °C for 30 min and purification by chroma-
tography on silica gel (hexane–EtOAc, 8:2) gave 18 (985 mg, 93%,
dr 95:5) as a colourless oil.
13C NMR (125.8 MHz, CD3OD): d = 14.4 (q, CH3), 23.7 (t, CH2),
30.37, 30.43, 30.6, 30.69, 30.71, 30.73, 30.74, 32.7, 33.0, 36.9 (10
t, CH2), 60.2 (d, CH), 61.2 (t, C-1), 73.4 (d, CH), 124.7, 127.4,
129.0, 129.5 (4 d, Ar), 142.1, 144.4 (2 s, Ar).
MS (EI, 80 eV, 170 °C): m/z (%) = 335 (4, [M]+), 317 (4, [M –
H2O]+), 304 (6, [M – CH3O]+), 275 (100, [M – C2H6NO]+), 60 (45,
[C2H6NO]+).
(2S,3R)-2-(tert-Butoxycarbonylamino)-3-(3-dodecylphenyl)-
propane-1,3-diol (6)
According to the procedure described for synthesis of 5, treatment
of 17 (360 mg, 0.76 mmol) with a mixture of AcOH–H2O (10:1, 3
mL) with LiCl (65 mg, 1.51 mmol) and purification by chromatog-
raphy on silica gel (hexane–EtOAc, 1:1) gave 6 (321 mg, 96%) as a
colourless solid; mp 72 °C (Lit.11 mp 76.5–77.5 °C).
HRMS (EI, 80 eV, 170 °C): m/z calcd for C21H35NO2 [M – H2O]+:
317.27255; found: 317.27185.
IR (KBr): 3420 (O–H), 3055 (=C–H), 2980–2850 (C–H), 1680
(C=O), 1535, 1470, 1390, 1370, 1310, 1250, 1180, 1090, 1005
cm–1.
(2S,3R)-2-Amino-3-(3-dodec-1-enylphenyl)propane-1,3-diol
(22)
According to the procedure described for synthesis of 21, a mixture
of 7 (200 mg, 0.46 mmol) and TFA (408 mL, 5.49 mmol) in CH2Cl2
(8 mL) was stirred overnight at r.t. After purification by column
1H NMR (500 MHz, CDCl3): d = 0.86 (t, J = 7.1 Hz, 3 H, CH3),
1.20–1.33 (m, 18 H, 9 CH2), 1.43 [s, 9 H, C(CH3)3], 1.54–1.62 (m,
2 H, CH2), 2.58 (t, J = 8.0 Hz, 2 H, CH2), 3.57 (dd, J = 4.2, 11.9 Hz,
1 H, 1-H), 3.77 (br s, 2 H, 1-H, 2-H), 5.01 (br s, 1 H, 3-H), 5.46 (br
s, 1 H, NH), 7.06–7.28 (m, 4 H, Ar).
Synthesis 2009, No. 5, 759–766 © Thieme Stuttgart · New York

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Syntheses of Sphingosine-1-Phosphate and Analogues
765
chromatography on silica gel (CH2Cl2–MeOH, 8:2), 22 (149 mg,
97%, dr > 95:5) was obtained as a colourless solid; mp 62 °C; [a]D
–10.3 (c 0.3, MeOH).
1H NMR (500 MHz, CDCl3): d = 0.87 (t, J = 6.9 Hz, 3 H, CH3),
1.14–1.31 (m, 18 H, 9 CH2), 1.37 [s, 9 H, C(CH3)3], 1.52–1.66 (m,
2 H, CH2), 2.58 (t, J = 7.1 Hz, 2 H, CH2), 3.18 (d, J = 4.3 Hz, 1 H,
OH), 3.74, 3.77 (2 d, JHP = 11.3 Hz, 3 H each, OCH3), 3.19–4.12
(m, 2 H, 1-H, 2-H), 4.24–4.35 (m, 1 H, 1-H), 4.78 (br s, 1 H, 3-H),
5.08 (d, J = 7.4 Hz, 1 H, NH), 7.05–7.29 (m, 4 H, Ar).
13C NMR (125.8 MHz, CDCl3): d = 14.1 (q, CH3), 22.6 (t, CH2),
28.2 [q, C(CH3)3], 29.3, 29.5, 29.6, 29.69, 29.72, 29.76, 29.77, 31.9
(8 t, CH2), 54.6 (qd, JCP = 6.2 Hz, OCH3), 55.9–56.0 (br, C-2),
66.3–66.3 (br, C-1), 73.7 (d, C-3), 79.2 [s, C(CH3)3], 123.5, 126.3,
127.8, 128.2 (4 d, Ar), 140.3, 143.1 (2 s, Ar), 155.5 (s, C=O).
IR (KBr): 3380 (O–H), 2955–2855 (=C–H, C–H), 1680, 1440,
1205, 1140, 1050, 965 cm–1.
1H NMR (500 MHz, CD3OD): d = 0.89 (t, J = 7.3 Hz, 3 H, CH3),
1.30–1.34 (m, 16 H, 8 CH2), 1.47–1.48 (m, 2 H, CH2), 2.21–2.23
(m, 2 H, CH2), 3.34–3.35 (m, 1 H, CH), 3.65 (br s, 2 H, 1-H), 4.91
(br s, 1 H, CH), 6.27–6.32 (m, 1 H, =CH), 6.41 (d, J = 15.8 Hz, 1
H, =CH), 7.23–7.41 (m, 4 H, Ar).
13C NMR (125.8 MHz, CD3OD): d = 14.4 (q, CH3), 23.7, 30.3, 30.4,
30.5, 30.6*, 33.01, 33.02, 34.0 (7 t, CH2), 49.8 (d, CH), 55.0 (t, C-
1), 66.0 (d, CH), 124.7, 125.6, 126.7, 129.8 (4 d, Ar), 130.9, 132.5
(2 d, =CH), 139.7, 142.0 (2 s, CAr). * Signal with higher intensity.
31P NMR (202 MHz, CDCl3): d = 2.57.
MS (EI, 80 eV, 100 °C): m/z (%) = 543 (<1, [M]+), 443 (1, [M –
NHBoc]+), 127 (100), 57 (17, [C4H9]+).
MS [FAB (+), MNBA–CH2Cl2]: m/z (%) = 334 (19, [M + H]+), 316
(5, [M – H2O]+), 286 (7, [M – CH5ON]+), 154 (22), 91 (56,
[C3H8NO2]+), 55 (87), 43 (100).
Dimethyl (2S,3R)-2-(tert-Butoxycarbonylamino)-3-(hydroxy-3¢-
dodec-1¢¢-enylphenyl)prop-1-ylphosphate (25)14
According to the procedure described for compound 23, a mixture
of alcohol 7 (200 mg, 0.46 mmol), CBr4 (192 mg, 0.58 mmol), and
P(OMe)3 (77 mL, 0.65 mmol) in pyridine (2.3 mL) was stirred at r.t.
for 3 h. After workup and purification on silica gel (hexane–EtOAc
2:8), phosphate 25 (190 mg, 76%, dr >95:5) was obtained as a co-
lourless solid; mp 55 °C; [a]D –7.5 (c 0.26, CHCl3).
HRMS (EI, 80 eV, >200 °C): m/z calcd for C19H28O [M – C2H6NO
– H]+: 272.21366; found: 272.21402.
Dimethyl (2S,3R,4E)-2-(tert-Butoxycarbonylamino)-3-hydroxy-
octadec-4-en-1-ylphosphate (23)14
To a solution of 5 (511 mg, 1.28 mmol) and CBr4 (530 mg, 1.60 mL)
in pyridine (3 mL) at 0 °C was added P(OMe)3 (212 mL, 1.80
mmol). The mixture was allowed to warm up to r.t., stirred for 3 h,
then diluted with Et2O (20 mL), and quenched with aq 1 N HCl so-
lution (20 mL). The aqueous phase was extracted with Et2O (2 × 20
mL). The combined organic phases were washed with aq sat.
NaHCO3 solution (20 mL), brine (20 mL), dried (MgSO4), and con-
centrated. Chromatography of the residue on silica gel (hexane–
EtOAc, 2:8) gave 23 (435 mg, 67%, dr 99:1) as a yellow oil; [a]D
+3.9 (c 1.23, CHCl3) {Lit.14 [a]D +4.3 (c 1.00, CHCl 3)}.
IR (KBr): 3370 (O–H), 3065–3010 (=CH), 2980–2850 (C–H), 1690
(C=O), 1530, 1460, 1370, 1270, 1250, 1180, 965, 860 cm–1.
1H NMR (500 MHz, CDCl3): d = 0.88 (t, J = 6.8 Hz, 3 H, CH3),
1.27–1.33 (m, 14 H, 7 CH2), 1.36 [s, 9 H, C(CH3)3], 1.43–1.48 (m,
2 H, CH2), 2.19 (q, J = 6.8 Hz, 2 H, CH2), 3.70 (d, JHP = 11.4 Hz, 3
H, OCH3), 3.73 (d, JHP = 11.3 Hz, 3 H, OCH3), 3.94 (br s, 1 H, OH),
4.02–4.06 (m, 2 H, 1-H, 2-H), 4.29–4.32 (m, 1 H, 1-H), 4.83 (br s,
1 H, 3-H), 5.34 (d, J = 8.9 Hz, 1 H, NH), 6.21–6.27 (m, 1 H, =CH),
6.35 (d, J = 15.8 Hz, 1 H, =CH), 7.23–7.34 (m, 4 H, Ar).
13C NMR (125.8 MHz, CDCl3): d = 14.2 (q, CH3), 22.7 (t, CH2),
28.3 [q, C(CH3)3], 29.3, 29.36, 29.39, 29.65, 29.66, 29.7, 32.0, 33.1
(8 t, CH2), 54.4-54.5 (br, OCH3), 55.9–60.0 (br, C-2), 66.2–66.3 (br,
C-1), 73.7 (d, C-3), 79.7 [s, C(CH3)3], 123.9, 124.7, 125.4, 128.6 (4
d, Ar), 129.6, 131.7 (2 d, =CH), 138.1, 140.9 (2 s, Ar), 155.7 (s,
C=O).
IR (KBr): 3370 (O–H), 2955–2850 (=CH, CH), 1715 (C=O), 1530,
1250, 1175, 1045, 850 cm–1.
1H NMR (500 MHz, CDCl3): d = 0.78 (t, J = 6.9 Hz, 3 H, CH3),
1.10–1.29 (m, 22 H, 11 CH2), 1.33 [s, 9 H, C(CH3)3], 1.93 (q, J = 7.1
Hz, 2 H, CH2), 3.75–3.80 (m, 1 H, 2-H), 3.76, 3.78 (2 d, JHP = 11.1
Hz, 3 H each, OCH3), 4.05–4.18 (m, 2 H, 1-H, 3-H), 4.28–4.35 (m,
1 H, 1-H), 5.19 (d, J = 9.0 Hz, 1 H, NH), 5.40 (dd, J = 6.9, 15.2 Hz,
1 H, 4-H), 5.76 (td, J = 7.1, 15.2 Hz, 1 H, 5-H). The spectroscopic
data fit with the values given in ref. 14.
31P NMR (202 MHz, CDCl3): d = 2.55.
MS [FAB (+), MNBA–CH2Cl2]: m/z (%) = 564 (6, [M + Na]+), 542
(3, [M + H]+), 441 (9), 154 (100), 57 (45, [C4H9]+).
13C NMR (125.8 MHz, CDCl3): d = 13.9 (q, CH3), 22.5 (t, CH2),
28.1 [q, C(CH3)3], 29.1*, 29.3, 29.5, 29.62, 29.65, 29.7, 31.7*, 31.8
(8 t, CH2), 54.4, 54.5 (2 qd, JCP = 5.7 Hz, OCH3), 54.9 (br s, C-2),
66.7 (td, JCP = 5.7 Hz, C-1), 72.1 (d, C-3), 79.2 [s, C(CH3)3], 128.6,
134.0 (2 d, C-4, C-5), 155.5 (s, C= O). * Signal with higher intensi-
ty.
MS (EI, 80 eV, 110 °C): m/z (%) = 541 (<1, [M]+), 273 (100,
[C19H29O]+).
HRMS (EI, 80 eV, 110 °C): m/z calcd for C28H48NO7P: 541.31684;
found: 541.316771.
(2S,3R)-2-(tert-Butoxycarbonylamino)-3-hydroxyoctadec-4-en-
1-ylphosphate (S1P, 1)14
The spectroscopic data fit with the values given in ref. 6c.
31P NMR (202 MHz, CDCl3): d = 2.59.
MS [FAB (+), MNBA–CH2Cl2]: m/z (%) = 530 (27, [M + Na]+),
508 (4, [M + H]+), 408 (23, [M + H – NHBoc]+), 264 (41), 126 (100,
[OPO(OCH3)2]+), 57 (17, [C4H9]+).
To a solution of 23 (576 mg, 1.13 mmol) in CH2Cl2 (60 mL) at 0 °C
was added Me3SiBr (674 mL, 5.11 mmol). After stirring at r.t. for 1
h, the reaction mixture was concentrated under reduced pressure.
Then, the residue was dissolved in MeOH (95%, 60 mL), stirred for
1 h, and concentrated. The colourless crude solid was recrystallised
twice from THF–H2O (2:1, 30 mL) to give S1P (1) (226 mg, 53%,
dr >95:5) as a colourless solid (according to HPLC 98% pure), mp
>150 °C (dec.) (Lit.16a mp >143 °C); [a]D –0.9 (c 0.26, AcOH)
{Lit.16a [a]D –1.22 (c 0.40, AcOH)}.
1H NMR (500 MHz, CD3CO2D): d = 0.89 (t, J = 6.4 Hz, 3 H, CH3),
1.14–1.46 (m, 22 H, 11 CH2), 2.09 (q, J = 6.9 Hz, 2 H, CH2), 3.60–
3.77 (m, 1 H, 2-H), 4.17–4.32 (m, 2 H, 1-H), 4.43–4.57 (m, 1 H, 3-
H), 5.55 (dd, J = 7.0, 15.2 Hz, 1 H, =CH), 5.92 (td, J = 7.3, 15.2 Hz,
1 H, =CH).
Dimethyl (2S,3R)-2-(tert-Butoxycarbonylamino)-3-(hydroxy-3-
dodecylphenyl)prop-1-ylphosphate (24)2,14
According to the procedure described for synthesis of 23, a mixture
of 6 (321 mg, 0.74 mmol), CBr4 (323 mg, 0.96 mmol), and P(OMe)3
(130 mL, 1.09 mmol) in pyridine (3.7 mL) was stirred at r.t. for 3 h.
After workup and purification on silica gel (hexane–EtOAc 2:8), 24
(270 mg, 67%, dr >95:5) was obtained as a colourless solid; mp 57–
59 °C; [a]D –1.6 (c = 0.52, CHCl3).
IR (KBr): 3360 (O–H), 3060–3000 (=CH), 2960–2855 (C–H), 1715
(C=O), 1525, 1470, 1365, 1255, 1175, 1045, 855 cm–1.
31P NMR (202 MHz, CD3CO2D): d = 2.51 (Lit.16b d = 2.42).
Synthesis 2009, No. 5, 759–766 © Thieme Stuttgart · New York

766
V. Blot et al.
PAPER
The spectroscopic data fit with the values given in ref. 16b.
(5) For recent reviews on chemistry and biology of sphingosine
derivatives, see: (a) Liao, J.; Tao, J.; Lin, G.; Liu, D.
Tetrahedron 2005, 61, 4715. (b) Koskinen, P. M.;
Koskinen, A. M. P. Synthesis 1998, 1075.
(2S,3R)-2-(tert-Butoxycarbonylamino)-3-(hydroxy-3¢-dodecyl-
phenyl)prop-1-ylphosphate (3)2,14
According to the procedure described for compound 1, a mixture of
phosphate 24 (260 mg, 0.48 mmol), Me3SiBr (295 L, 2.24 mmol) in
CH2Cl2 (25 mL) was stirred r.t. for 1 h. After concentration of the
reaction mixture, MeOH (95%, 25 mL) was added, the mixture was
stirred for 1 h and concentrated. The crude product was precipitated
in (AcOH–H2O) and then crystallised from THF–H2O (2:1) to af-
ford phosphate 3 (64 mg, 32%, dr >95:5) as a colourless solid; mp
>150 °C (dec.); [a]D –10.5 (c 0.14, AcOH).
1H NMR (500 MHz, CD3CO2D): d = 0.89 (t, J = 7.0 Hz, 3 H, CH3),
1.23–1.40 (m, 18 H, CH2), 1.59–1.67 (m, 2 H, CH2), 2.58 (t, J = 7.1
Hz, 2 H, CH2), 3.86–3.93 (m, 1 H, 2-H), 4.09–4.17 (m, 1 H, 1-H),
4.28–4.33 (m, 1 H, 1-H), 5.12 (d, J = 5.5 Hz, 1 H, 3-H), 7.05–7.29
(m, 4 H, Ar).
(6) For publications on the synthesis of D-(2S,3R)-sphingosine
and references cited, see: (a) Merino, P.; Jimenez, P.;
Tejero, T. J. Org. Chem. 2006, 71, 4685. (b) Kim, S.; Lee,
S.; Ko, H.; Kim, D. J. Org. Chem. 2006, 71, 8661.
(c) Yamamoto, T.; Hasegawa, H.; Hakogi, T.; Katsumura, S.
Org. Lett. 2006, 8, 5569. (d) Yang, H.; Liebeskind, L. S.
Org. Lett. 2007, 9, 2993.
(7) For selected publications on recent synthesis of sphingosine
analogues, see: (a) Grijalvo, S.; Llebaria, A.; Delgado, A.
Synth. Commun. 2007, 37, 2737. (b) Kim, S.; Lee, Y. M.;
Kang, H. R.; Cho, J.; Lee, T.; Kim, D. Org. Lett. 2007, 9,
2127; and references cited therein.
(8) For other syntheses of sphingosine using L-serine, see:
(a) Radunz, H. E.; Devant, R. M.; Eiermann, V. Liebigs Ann.
Chem. 1988, 1103. (b) Herold, P. Helv. Chim. Acta 1988,
71, 354. (c) Garner, P.; Park, J. M.; Malecki, E. J. Org.
Chem. 1988, 53, 4395. (d) Nimkar, S.; Menaldino, D.;
Merrill, A. H.; Liotta, D. Tetrahedron Lett. 1988, 29, 3037.
(e) Soai, K.; Takahashi, K. J. Chem. Soc., Perkin Trans. 1
1994, 1257. (f) Azuma, H.; Tamagaki, S.; Ogino, K. J. Org.
Chem. 2000, 65, 3538. (g) Murakami, T.; Furusawa, K.
Tetrahedron 2002, 58, 9257. (h) Chun, J.; Li, G.; Byun, H.-
S.; Bittman, R. Tetrahedron Lett. 2002, 43, 375. (i) Suzuki,
H.; Mori, M.; Shibakami, M. Synlett 2003, 2163.
(j) Sawatzki, P.; Kolter, T. Eur. J. Org. Chem. 2004, 3693.
(k) Murakami, T.; Furusawa, K.; Tamai, T.; Yoshikai, K.;
Nishikawa, M. Bioorg. Chem. Med. Lett. 2005, 15, 1115.
(l) Okamoto, N.; Kanie, O.; Huang, Y.-Y.; Fujii, R.;
Watanabe, H.; Shimamura, M. Chem. Biol. 2005, 12, 677.
(m) Reference 6c. (n) Ohshita, K.; Ishiyama, H.; Takahashi,
Y.; Ito, J.; Mikami, Y.; Kobayashi, J. Bioorg. Med. Chem.
2007, 15, 4910.
31P NMR (202 MHz, CD3CO2D): d = 2.45.
(2S,3R)-2-(tert-Butyloxycarbonyl)amino-3-(hydroxy-3¢-dodec-
1¢¢-enylphenyl)prop-1-ylphosphate (4)14
According to the procedure described for compound 1, a mixture of
phosphate 25 (141 mg, 0.26 mmol), Me3SiBr (155 mL, 1.17 mmol)
in CH2Cl2 (13 mL) was stirred at 0 °C for 1 h. After concentration
of the reaction mixture, MeOH (95%, 12 mL) was added, the mix-
ture was stirred for 1 h, and concentrated. The crude product was
precipitated with AcOH–H2O, then the precipitate was filtered and
washed with acetone (15 mL). After crystallisation of the precipi-
tate from THF–H2O (2:1), phosphate 4 (57 mg, 59%, dr >95:5) was
obtained as a colourless solid; mp >145 °C (dec.), [a]D +2.5 (c 0.2,
AcOH).
IR (KBr): 3385 (O–H), 3060, 3020 (=C–H), 2955–2855 (CH),
1630, 1605, 1465, 1330, 1170, 1055 cm–1.
1H NMR (500 MHz, CD3CO2D): d = 0.88 (t, J = 6.7 Hz, 3 H, CH3),
1.29–1.34 (m, 16 H, 8 CH2), 1.46–1.50 (m, 2 H, CH2), 2.22 (t,
J = 7.0 Hz, 2 H, CH2), 3.90–3.94 (m, 1 H, 2-H), 4.13–4.17, 4.28–
4.31 (2 m, 1 H each, 1-H), 5.12 (d, J = 5.5 Hz, 1 H, 3-H), 6.30–6.43
(m, 2 H, =CH), 7.24–7.40 (m, 3 H, Ar), 7.45 (s, 1 H, Ar).
(9) For reviews concerning Garner’s aldehyde, see: Liang, X.;
Andersch, J.; Bols, M. J. Chem. Soc., Perkin Trans. 1 2001,
2136.
(10) (a) Dondoni, A.; Perrone, D. Synthesis 1997, 527.
(b) Williams, L.; Zhang, Z.; Shao, F.; Carroll, P. J.; Joullié,
M. M. Tetrahedron 1996, 52, 11673. (c) Yonezawa, Y.;
Shimizu, K.; Yoon, K.-S.; Shin, C.-G. Synthesis 2000, 634.
(11) Chun, J.; He, L. L.; Byun, H. S.; Bittman, R. J. Org. Chem.
2000, 65, 7634.
31P NMR (202 MHz, CD3CO2D): d = 2.45.
Anal. Calcd for C21H36NO5P (413.2): C, 61.00; H, 8.78; N, 3.39.
Found: C, 60.49; H, 8.79; N, 3.25.
(12) Review on ionic hydrogenations: Kursanov, D. N.; Parnes,
Z. N.; Loim, M. M. Synthesis 1974, 633.
(13) Selected applications of ionic hydrogenations: (a) Kraus, G.
A.; Frazier, K. A.; Roth, B. D.; Taschner, M. J.;
Acknowledgment
Support of this work by the Deutsche Forschungsgemeinschaft
(Forschergruppe 463), the Fonds der Chemischen Industrie, and the
Bayer Schering Pharma AG is most gratefully acknowledged. We
thank Dr. R. Zimmer for his help during the preparation of the ma-
nuscript.
Neuenschwander, K. J. Org. Chem. 1981, 46, 2417.
(b) Kraus, G. A.; Molina, M. T.; Walling, J. A. J. Org. Chem.
1987, 52, 1273. (c) Badirad, S. A.; Wang, Y.; Kishi, Y.
J. Org. Chem. 1987, 52, 1370. (d) Brückner, C.; Holzinger,
H.; Reissig, H.-U. J. Org. Chem. 1988, 53, 2450. (e) Arndt,
S.; Emde, U.; Bäurle, S.; Friedrich, T.; Grubert, L.; Koert, U.
Chem. Eur. J. 2001, 7, 993.
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S1P 1 in quantities of more than 100 g.
Synthesis 2009, No. 5, 759–766 © Thieme Stuttgart · New York