Design and synthesis of new KRN7000 analogues

Article abstract of DOI:10.1016/j.tet.2013.06.051

Presented by CD1d protein, KRN7000, a potent synthetic α- galactosylceramide, is known to stimulate the iNKT cells to produce different bioactive cytokines. Six new KRN7000 analogues, in which the amide bond in KRN7000 is replaced with O, NH, or ester groups incorporating variation of the acyl chain, or possessing an additional four-atom linker between the galactose and phytosphingosine moiety, were designed and synthesized. The synthetic compounds were evaluated for their ability to stimulate cytokine release and the preliminary structure-activity relationships were discussed. The synthetic strategy will benefit the construction of more KRN7000 derivatives, which may contribute to cytokine profile bias.

Full text of DOI:10.1016/j.tet.2013.06.051

Tetrahedron 69 (2013) 7438e7447
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Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Design and synthesis of new KRN7000 analogues
*
Man Sun, Yuhang Wang, Xin-Shan Ye
State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road No. 38,
Beijing 100191, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 23 April 2013
Received in revised form 29 May 2013
Accepted 13 June 2013
Available online 21 June 2013
Presented by CD1d protein, KRN7000, a potent synthetic a-galactosylceramide, is known to stimulate the
iNKT cells to produce different bioactive cytokines. Six new KRN7000 analogues, in which the amide bond
in KRN7000 is replaced with O, NH, or ester groups incorporating variation of the acyl chain, or possessing
an additional four-atom linker between the galactose and phytosphingosine moiety, were designed and
synthesized. The synthetic compounds were evaluated for their ability to stimulate cytokine release and
the preliminary structureeactivity relationships were discussed. The synthetic strategy will benefit the
construction of more KRN7000 derivatives, which may contribute to cytokine profile bias.
Ó 2013 Elsevier Ltd. All rights reserved.
Keywords:
KRN7000 analogue
Glycolipid
a
-GalCer
Carbohydrate
Synthesis
1. Introduction
a-galactosylceramide (a-GalCer) generated from the structural
modification of the marine natural product agelasphin-9b, is the
prototypical ligand to stimulate iNKT cells when presented by CD1d
expressed on the surface of antigen-presenting cells (APC).5 How-
ever, the controversial effects resulted from both high level in-
ductions of Th1 and Th2 cytokines and the anergic state of iNKT
cells induced by KRN7000 limited its value in therapeutic appli-
cations.6 Therefore, more effective antigens, which can selectively
control the cytokine release profile by NKT cells toward either Th1
or Th2 were extensively explored.7
Invariant natural killer T (iNKT) cells are regulatory T cells that
display characteristics of both T cells and NK cells.1 Mediated by
semi-invariant T cell receptor (TCR), iNKT cells recognize bacterial
or endogenous glycolipid antigens presented by CD1d, an antigen
presenting protein related to major histocompatibility complex
proteins.2 Once stimulated, iNKT cells can elicit a number of cyto-
kines, including pro-inflammatory T helper 1 (Th1) cytokines (e.g.,
IFN-g
, IL-2) and anti-inflammatory Th2 cytokines (e.g., IL-4).3 Th1
cytokines are thought to be related to the antitumor, antiviral, and
antibacterial activities, whereas Th2 cytokines may help to alleviate
autoimmune diseases.4 KRN7000 (Fig. 1), a synthetic glycolipid
So far there have been a number of KRN7000 derivatives in-
cluding modifications of the sugar moiety, the polar portion of the
ceramide, the two lipid chains, and the glycosidic linkage.7a,8 Some
of them succeeded in leading to changes in the cytokine release
profile, presumably through alteration of glycolipid/CD1d complex
stability. For example, a-GalCer derivative 2 (PBS-25) with a shorter
fatty acid chain have shown to induce a predominant production of
Th2 cytokine over Th1 compared with that of KRN7000.9 Com-
pound 3 with introduction of an aromatic group to the fatty acid
chain enhances the Th1 cytokine profile (Fig. 1).10 The replacement
of an amide function with an isosteric group, such as a triazole
increases the IL-4 versus IFN-
placement of the anomeric oxygen of
g
bias of released cytokines.11 Re-
-GalCer by CH2, the C-gly-
a
coside variant of KRN7000 stimulates strong Th1 responses in vivo
from NKT cells.12 Although advances on syntheses of KRN7000
analogues with improved activities have been achieved, the dis-
covery of new KRN7000 derivatives with more potent properties is
still in great demand. Herein we report the preparation of several
new KRN7000 analogues with the modifications at the amide bond.
Fig. 1. Chemical structures of 1, 2, 3.
* Corresponding author. Fax: þ86 10 82802724; e-mail address: xinshan@
bjmu.edu.cn (X.-S. Ye).
0040-4020/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tet.2013.06.051

M. Sun et al. / Tetrahedron 69 (2013) 7438e7447
7439
2. Results and discussion
The structureeactivity relationship (SAR) studies of
a
-GalCer
were aided by two crystal structures of both mouse (m) and human
(h) CD1d complex with 1 and by a ternary structure of hCD1d/
KRN7000/hTCR complex.13 The crystallographic studies identified
that the lipid chains of a-GalCer were accommodated in the antigen-
binding groove, consisting of two channels, lined with hydrophobic
residues. Besides hydrophobic interactions, there are several
hydrogen-bonding interactions between the surface residues of
CD1d and the hydroxyl groups of KRN7000, which are considered to
contribute to maintain KRN7000 in the correct position and orien-
tation for recognition by the TCR. One of the hydrogen-bonding
interactions is identified as the Thr156 of mCD1d with NH of the
amide group of KRN7000 acting as an H-bond donor. In view of
substitution of the amide group including triazole,11 sulfonamide,14
azetidine or pyrrolidine ring15 and recently reported ester group,16 it
is seemed that the functional groups substituting amide of KRN7000
are mostly able to form H-bond.
In an effort to understand whether this H-bond ability is crucial
for the activity and how this replacement influences cytokine profile,
we designedthree KRN7000 analogues4, 5, and6 (Fig. 2) inwhichthe
amide group was replaced with an ether or amino group, combining
variations of the acyl chain from compounds 2 and 3. To evaluate
whether the two lipid chains of analogues linked at different hy-
droxyl positions can fit intothe CD1d bindinggroove like KRN7000 or
not, we decidedto synthesizebothetherand esterderivatives(8, 9)as
target molecules (Fig. 2). It was shown that an isoglobotrihexosyl-
Scheme 1. Reagents and conditions: (a) AllBr, NaH, DMF, 0 ꢀC, 95%; (b) HCl, MeOH,
quant.; (c) NaIO4/H2O, THF, 96%; (d) NaBH4, MeOH, 91%; (e) TrCl, Py, 50 ꢀC; (f) BnBr,
NaH, DMF, 0 ꢀC; (g) HOAc/H2O, 60 ꢀC, 80%; (h) PdCl2, MeOH, 84%.
with N-iodosuccinimide (NIS) will lead to byproducts resulting
from the addition of electrophiles to the double bond of allyl
group.20 To avoid this, the allyl group in 13 was removed to afford
glycosyl acceptor 14.
With acceptor 14 in hand, the glycosylation reaction was carried
out. As shown in Scheme 2, the coupling reaction of acceptor 14 and
donor 1521 with NIS/TfOH as promoter provided the desired
a
-anomer 16
donors, such as p-methylphenyl 2,3-di-O-benzyl-4,6-O-benzyli-
dine-1-thio-
-galactopyranoside21 were also attempted for the
glycosylation of acceptor 14, but they resulted in a small or no
amount of the desired configuration products with either NIS/
TfOH or BSM/Tf2O22 as promoter. Subsequently, an attempt to
a as well as separable products 16b, 17a, 17b. Other
b-D
a
convert 16
a
to its triflate under the conditions of Tf2O/KNO2/DMF,
ceramide (iGb3), which is a b-linked trihexosyl ceramide and may
be an endogenous ligand for iNKT cells, stimulating both human and
mouse NKTcells.17 Itwassuggested thatthe variabilityof the NKTTCR
b-chain enabled the accommodation of iGb3 via a different confor-
mation of TCR or ‘squashed’ iGb3 headgroup.13c,18 Comparing the
larger trihexosyl headgroup of iGb3 with the simple galactose sugar
ofKRN7000, we designed compound7 (Fig. 2), which has a four-atom
linker between the sugar and ceramide part of KRN7000 via amide
group to investigate the influence on cytokine profile. As far as we
know, the linkage between the sugar and ceramide of KRN7000 has
been less studied in the literature.
Fig. 2. Designed target KRN7000 analogues.
We therefore turned our attention to the synthesis of the target
molecules. First of all, we decided to synthesize diol 14 as a glycosyl
acceptor and invert the hydroxyl configuration after glycosylation
(Scheme 1). Treatment of alcohol 1019 with allyl bromide and NaH,
followed by removal of the propylidene group with acid, afforded
compound 11. Cleavage of the hydroxylmethylene arm in 11 by
sodium periodate and further treatment with sodium borohydride,
gave triol 12 in good yield. Regioselective protection of the primary
hydroxyl group in 12 with trityl chloride and subsequent protection
of the remaining free secondary hydroxyl groups as benzyl ether,
followed by removal of the trityl group, provided intermediate 13 in
80% isolated yield. It is possible that the subsequent glycosylation
ꢀ
Scheme 2. Reagents and conditions: (a) NIS, TfOH, 4 A MS, CH2Cl2, 43% for 16
a, 11% for
ꢀ
17
steps (18:16
(e) H2, Pd/C, CH2Cl2/MeOH, 98% for 4, 96% for 5.
a, 18% for 16
b, 9% for 17
b
; (b) PCC, 4 A MS, CH2Cl2; (c) NaBH4, MeOH, 98% over two
¼1.6:1.0); (d) 19 and 20, KOH, toluene, reflux, 85% for 21, 65% for 22;
a

7440
M. Sun et al. / Tetrahedron 69 (2013) 7438e7447
which was followed by an SN2 displacement with 8-phenyloctan-1-
ol using NaH as base to directly afford product 21 with desired
stereochemistry, was proved to fail. Fortunately, oxidation of 16
a
with PCC followed by reduction with NaBH4 eventually resulted in
compound 18 with the inversion of C-2 configuration as the major
product as well as the recovery of starting material 16a in a ratio of
1.6:1. The substitution reaction of 18 with 8-phenyl-1-octanolyl
p-toluenesulfonate 1923 and 1-octlyl p-toluenesulfonate 2024 yiel-
ded compounds 21 and 22, respectively. Then, the catalytic hydro-
genolysis of 21 and 22 gave the target compounds 4 and 5 very
smoothly.
We were inclined to invert the C3eOH configuration of the re-
ported intermediate 10 in the beginning for the synthesis of target
compounds 4 and 5. However, the SN2 displacement of the mesy-
late or triflate of 10 with KOH gave no desired configuration in-
version product but elimination product. It gave the same results
when the mesylate or triflate of 10 was treated with allyl alcohol/
NaH. Both the Mitsunobu reaction (allyl alcohol,25 acetic acid or p-
nitrobenzoic acid as nucleophile) and oxidation (TEMPO,26 PCC,
PDC, the Swern reagent, and the DesseMartin reagent) followed by
reduction failed to provide the desired inversion product, which
may result from the steric hindrance of the two propylidene pro-
tecting groups in the proximity of hydroxyl group. Moreover,
treatment of the triflate of 10 with KNO2 in DMF proceeded,27 but it
only produced a trace amount of configuration inversion product.
Scheme 4. Reagents and conditions: (a) TBSOTf, 2,6-lutidine, CH2Cl2; (b) CF3COOH,
ꢀ
THF/H2O, 85% over two steps; (c) 15, NIS, TfOH, 4 A MS, CH2Cl2, 53% for 27
a, 27% for its
b-anomer; (d) TBAF, THF, 80%; (e) NaBH4, NiCl2$6H2O, MeOH; (f) Ph(CH2)7CHO,
NaBH3CN, AcOH, MeOH, 51%; (g) H2, Pd(OH)2/C, CH2Cl2/MeOH, 78%.
Coupling product 17
8 by the same strategy as described in the preparation of 4. On the
other hand, esterification of 17 with hexacosanoic acid, which was
a was transformed into the final compound
a
followed by hydrogenolysis, afforded another target molecule 9
(Scheme 3).
Scheme 5. Reagents and conditions: (a) TrCl, Py, 50 ꢀC; (b) BnBr/NaH/DMF; (c) HOAc/
H2O, 50 ꢀC, 80% over three steps; (d) PPh3/H2O, THF, 60 ꢀC; (e) C25H51COOH, HBTU,
DIPEA, CH2Cl2, 98% over two steps; (f) DIAB/TEMPO, CH2Cl2, 81%; (g) (i) DIAB/TEMPO,
CH2Cl2; (ii) NaClO2, NaH2PO4, Bu4NCl, CH2Cl2/H2O, 90%; (h) 33, HBTU, DIPEA, CH2Cl2,
71%; (i) H2, Pd(OH)2/C, CHCl3/MeOH/HOAc, 74%.
further by NaClO2/NaH2PO4 (30 min), was performed to give acid
32 in 90% yield. Coupling reaction of 32 and amine 33 afforded
compound 34, which was followed by catalytic hydrogenolysis over
Pd(OH)2/C to result in target molecule 7.
Scheme 3. Reagents and conditions: (a) 19, KOH, toluene, reflux, 85%; (b) H2, Pd/C,
CH2Cl2/MeOH, 97%; (c) C25H51COOH, EDC, DMAP, CH2Cl2, 55%; (d) H2, Pd(OH)2/C,
CH2Cl2/MeOH, 97%.
The synthetic compounds 4e9 were evaluated for their ability to
induce IL-4 and IFN-
g in vitro and in vivo, using KRN7000 as
With respect to analogue 6, we chose alcohol 26 as the glycosyl
acceptor, which was obtained from the known triol 2519 (Scheme 4).
Glycosylation of 26 with the galactosyl donor 15 was then per-
a positive control. It turned out that the analogues induced no
detectable cytokine or proliferative response.
The ether analogues 4 and 5 were completely inactive on murine
cells, which was consistent with the previous results reported pre-
viously.16 The ether analogues 4 and 5 as well as the amine analogue
6, which could be protonated at physiological pH, may be not able to
form a H-bond with Thr156 of mCD1d. Taking all amide modifica-
tions together, we speculate that the ability to form H-bond in-
volving H-bond donor and H-bond acceptor play a significant role in
the activity and cytokine profile of NKT cells. Moreover, the modi-
fications also increase the flexibility of the lipid chain, which may
cause a different orientation of the acyl lipid in the compound,
resulting in the analogues not to fit into the cavity of mCD1d. This
result gave further evidence on the conjecture that the amide
moiety of KRN7000 is crucial for maintaining the correct position
and orientation to fit into the binding cavity and to be recognized by
the TCR. The fact analogue 7 lost the activity may be attributed to the
formed, affording the desired
anomer. Cleavage of the TBS protecting group in 27
a
-galactoside 27
a
as the major
with TBAF gave
a
compound 28. Reduction of the azido group in 28 followed by
reductive amination provided compound 29. In the final step, all
benzyl protecting groups in 29 were removed with H2 over Pd(OH)2/
C to yield target compound 6.
The synthesis of analogue 7 started from the transformation of
triol 25 to compound 30 according to the reported procedure28
(Scheme 5). Reduction of azide 30 under the Staudinger condi-
tions followed by acylation with hexacosanoic acid furnished
alcohol 31 in excellent yield. Oxidation of 31 with DIAB/TEMPO
produced acid 32, it took relatively long time (3e4 days) and an
excess amount of reagent (3 equiv TEMPO). Thus an alternative
oxidation by using DIAB/TEMPO (2 equiv/1 equiv, overnight) and

M. Sun et al. / Tetrahedron 69 (2013) 7438e7447
7441
distance between the galactose and ceramide moiety, which was
also observed in C-KRN7000 analogue (increasing by one carbon).29
The suitable tolerant distance between the galactose and ceramide
part of KRN7000 needs to be investigated.
3.60 (t, J¼4.5 Hz, 1H), 1.69e1.59 (m, 2H), 1.58e1.48 (m, 2H), 1.46 (s,
3H), 1.41 (s, 3H), 1.40e1.22 (m, 28H), 0.88 (t, J¼7.0 Hz, 3H); 13C NMR
(125 MHz, CDCl3)
d 135.0, 116.2, 108.4, 108.2, 79.0, 77.7, 77.66, 77.5,
72.9, 66.2, 31.9, 29.7, 29.65, 29.6, 29.55, 29.4, 27.2, 26.5, 26.3, 26.0,
þ
In conclusion, six new KRN7000 analogues with the modifica-
tions at the amide bond or the linkage between the sugar and
ceramide were designed and synthesized. Although the synthetic
route for some target molecules was uneven, the desired com-
pounds were eventually prepared by the strategy that inverted the
hydroxyl configuration after the glycosidic bond construction.
These synthetic compounds were evaluated for their ability to
stimulate cytokine release and the preliminary structureeactivity
relationships were discussed. Although the compounds are inactive
on inducing the cytokine release, the results may be useful to guide
to design the next generation of KRN7000 analogues. On the other
hand, due to the potential applications of KRN7000 analogues in
drug discovery, the disclosed approach may facilitate preparation of
more KRN7000 derivatives with biological importance.
25.2, 22.7, 14.1; ESI-HRMS [MþNa]þ calcd for C28H52NaO5
491.3707, found 491.3703.
To a solution of above intermediate (2.23 g, 4.76 mmol) in MeOH
(15 mL) was added HCl (0.8 mL, 9.28 mmol) dropwise at 0 ꢀC and
the mixture was stirred at room temperature overnight. The sol-
vent was evaporated and the residue was purified by column
chromatography on silica gel (petroleum ether/EtOAc/MeOH
10:10:1) to give compound 11 as white solids (1.84 g,100%). 1H NMR
(500 MHz, CD3OD)
d
5.99e5.92 (m,1H), 5.39 (dq, J¼17.5, 2.0 Hz,1H),
5.11 (dq, J¼10.3, 1.5 Hz, 1H), 4.20e4.16 (m, 2H), 3.82e3.76 (m, 1H),
3.76e3.70 (m, 2H), 3.62e3.51 (m, 3H), 1.86e1.81 (m, 1H), 1.62e1.53
(m, 1H), 1.42e1.18 (m, 24H), 0.88 (t, J¼6.5 Hz, 3H); 13C NMR
(125 MHz, CD3OD)
d 136.6, 116.7, 79.0, 75.0, 74.4, 73.1, 72.0, 64.5,
35.2, 33.1, 31.0, 30.8, 30.5, 26.6, 23.7, 14.4; ESI-HRMS [MþH]þ calcd
þ
for C22H45O5 389.3262, found 389.3253.
3. Experimental
3.1. General
3.3. (2R,3R,4R)-2-O-Allyl-1,2,3,4-octadecanetetrol (12)
To a solution of compound 11 (1.1 g, 2.83 mmol) in THF (15 mL)
was added a solution of NaIO4 (0.6 g, 2.83 mmol) in H2O (15 mL) at
0 ꢀC and the mixture was stirred at 0 ꢀC for 1 day. The solvent was
evaporated and the resulting residue was purified by column
chromatography on silica gel (petroleum ether/EtOAc 2:1) to give
the intermediate as white solids (0.96 g, 96%). 1H NMR (500 MHz,
Air- and/or moisture-sensitive reactions were carried out under
an atmosphere of argon using flame-dried glassware and standard
syringe/septa techniques. All chemicals were purchased as reagent
grade and used without further purification, unless otherwise
noted. Dichloromethane (CH2Cl2) and pyridine were distilled over
calcium hydride (CaH2). Methanol was distilled from magnesium.
DMF was stirred with CaH2 and distilled under reduced pressure.
Tetrahydrofuran (THF) was distilled over sodium/benzophenone.
All reactions were carried out under anhydrous conditions with
freshly distilled solvents, unless otherwise noted. Analytical TLC
was performed on silica gel 60-F254 precoated on aluminum plates
(E. Merck), with detection by UV (254 nm) and/or by staining with
acidic ceric ammonium molybdate. Solvents were evaporated un-
der reduced pressure and below 35 ꢀC (bath). Organic solutions of
crude products were dried over anhydrous Na2SO4. Column chro-
matography was performed employing silica gel (200e300 mesh).
1H NMR spectra were recorded on a JEOL AL-300, Varian INOVA-
500 or Advance DRX Bruker-400 spectrometers at 25 ꢀC. Chem-
ical shifts (in parts per million) were referenced to tetramethylsi-
CD3OD) d 5.99e5.88 (m, 1H), 5.34e5.27 (m, 1H), 5.22e5.13 (m, 2H),
4.18e4.08 (m, 2H), 3.94e3.89 (m,1H), 3.74e3.71 (m,1H), 3.68e3.55
(m, 1H), 1.69e1.58 (m, 1H), 1.52e1.43 (m, 1H), 1.42e1.24 (m, 24H),
0.89 (t, J¼7.0 Hz, 3H); 13C NMR (125 MHz, CD3OD)
d 136.1, 135.8,
117.5, 117.2, 101.5, 95.7, 92.2, 85.6, 83.0, 82.3, 81.1, 78.9, 72.3, 71.8,
36.4, 34.3, 33.1, 30.8, 30.77, 30.74, 30.5, 2þ6.9, 26.8, 23.7, 14.5; ESI-
TOF-MS [MþNa]þ calcd for C21H40NaO4 379, found 379; Anal.
Calcd for C21H40O4: C, 70.74; H, 11.31. Found: C, 70.79; H, 10.91.
To a solution of above intermediate (506 mg,1.42 mmol) in dried
MeOH (10 mL) was added NaBH4 (55 mg,1.42 mmol) at 0 ꢀC and the
mixture was stirred at room temperature for 4 h. The solvent was
evaporated and the resulting residue was purified by column
chromatography on silica gel (petroleum ether/EtOAc/MeOH
15:15:1) to give compound 12 as white solids (511 mg, 91%). 1H
lane (
d
¼0 ppm) in deuterated chloroform. 13C NMR spectra were
NMR (500 MHz, CD3OD)
d
6.00e5.93 (m, 1H), 5.28 (ddd, J¼17.5, 3.5,
obtained by using the same NMR spectrometers and were cali-
1.5 Hz, 1H), 5.12 (d, J¼10.3 Hz, 1H), 4.22 (ddt, J¼12.8, 5.5, 1.5 Hz, 1H),
4.13 (ddt, J¼12.5, 5.5, 1.5 Hz, 1H), 3.71e3.68 (m, 3H), 3.58 (dt, J¼2.5,
8.5 Hz, 1H), 3.37 (dd, J¼8.3, 1.5 Hz, 1H), 1.81e1.75 (m, 1H), 1.59e1.52
(m, 1H), 1.40e1.24 (m, 24H), 0.89 (t, J¼7.0 Hz, 3H); 13C NMR
brated with CDCl3
(
d
¼77.00 ppm) or CD3OD ( ¼49.00 ppm). Mass
d
spectra were recorded using a PE SCLEX QSTAR spectrometer. High-
resolution mass spectrometry was performed on a Bruker APEX IV.
Elemental analysis data were recorded on a Vario EL-III element
analyzer.
(125 MHz, CD3OD)
d 136.85, 116.9, 79.8, 75.4, 73.4, 72.1, 62.8, 34.8,
33.1, 31.0, 30.8, 30.5, 26.6, 23.7, 14.4; ESI-TOF-MS [MþNa]þ calcd for
C
21H42NaO4þ 381, found 381; Anal. Calcd for C21H42O4: C, 70.34; H,
3.2. (2R,3R,4R,5R)-3-O-Allyl-1,2,3,4,5-nonadecanepentol (11)
11.81. Found: C, 70.09; H, 11.53.
Sodium hydride (420 mg, 0.01 mol) was added to a solution of
(2R,3R,4R,5R)-3-hydroxy-1,2; 4,5-di-O-isopropylidenenonadecane
1019 (2.14 g, 0.005 mol) in dry DMF (15 mL) at 0 ꢀC. The reaction
mixture was stirred at the same temperature for 10 min before allyl
bromide (0.66 mL, 0.9 g, 0.0075 mol) was added. The mixture was
allowed to warm to room temperature and stirred for an additional
6 h. The mixture was poured into ice-water mixture and then
extracted with EtOAc. The combined organic extract was dried with
Na2SO4, and concentrated in vacuo. The residue was purified by
column chromatography on silica gel (petroleum ether/EtOAc 40:1)
to give the intermediate as a colorless oil (2.23 g, 95%). 1H NMR
3.4. (2R,3R,4R)-2-O-Allyl-3,4-di-O-benzyl-1,2,3,4-
octadecanetetrol (13)
A solution of 12 (175 mg, 0.448 mmol) and trityl chloride
(180 mg, 0.634 mmol) in dry pyridine (10 mL) was stirred at 50 ꢀC
for 5 h. Pyridine was evaporated under reduced pressure and the
residue was diluted with EtOAc, and washed with H2O, saturated
aqueous NaHCO3 solution and brine, dried with Na2SO4, and con-
centrated in vacuo. The residue was then dissolved in dry DMF
(8 mL) and then treated with 60% NaH (84 mg, 2.0 mmol) for 10 min
at 0 ꢀC. BnBr (0.16 mL, 256 mg, 1.5 mmol) was added and the
mixture was allowed to warm to room temperature and stirred for
an additional 4.5 h. After the solvent was removed in vacuo, the
residue was dissolved in water and extracted with EtOAc. The
(500 MHz, CDCl3)
d
5.94e5.86 (m, 1H), 5.31 (dq, J¼17.3, 1.5 Hz, 1H),
5.13 (dq, J¼10.5, 1.5 Hz, 1H), 4.31 (ddt, J¼12.8, 6.0, 1.5 Hz, 1H), 4.18
(ddt, J¼12.5, 5.0, 1.5 Hz, 1H), 4.12e4.06 (m, 3H), 4.03e3.98 (m, 2H),

7442
M. Sun et al. / Tetrahedron 69 (2013) 7438e7447
organic extraction was concentrated and then dissolved in a mix-
ture of HOAc and H2O (5:1, 6 mL). The mixture was stirred at 60 ꢀC
overnight. Then the mixture was diluted with EtOAc, and washed
with H2O, saturated aqueous NaHCO3 solution and brine, dried
with Na2SO4, and concentrated in vacuo. The residue was purified
by column chromatography on silica gel (petroleum ether/EtOAc
10:1) to give compound 13 as white waxy solids (211 mg, 80% for
(500 MHz, CDCl3)
d
7.33e7.21 (m, 30H), 5.02 (d, J¼4.0 Hz, 1H), 4.91
(d, J¼11.5 Hz, 1H), 4.81e4.68 (m, 5H), 4.60 (d, J¼12.0 Hz, 1H),
4.55e4.48 (m, 3H), 4.38 (dd, J¼16.0, 11.5 Hz, 2H), 4.16 (dd, J¼6.8,
5.0 Hz, 1H), 4.05 (dd, J¼10.0, 3.5 Hz, 1H), 3.94 (dd, J¼10.0, 3.0 Hz,
1H), 3.85 (d, J¼1.5 Hz, 1H), 3.81e3.67 (m, 5H), 3.52 (dd, J¼9.8,
7.5 Hz, 2H), 3.31 (dd, J¼9.5, 5.0 Hz,1H),1.72e1.65 (m, 2H),1.48e1.40
(m, 2H), 1.38e1.18 (m, 22H), 0.88 (t, J¼7.0 Hz, 3H); 13C NMR
three steps). 1H NMR (500 MHz, CDCl3)
d
7.36e7.25 (m, 10H),
(125 MHz, CDCl3) d 138.8, 138.75, 138.6, 138.5, 138.4, 137.6, 128.39,
5.95e5.87 (m, 1H), 5.24 (dd, J¼17.0, 1.5 Hz, 1H), 5.15 (dd, J¼10.3,
1.0 Hz, 1H), 4.74 (d, J¼11.5 Hz, 1H), 4.68 (d, J¼11.0 Hz, 1H), 4.60 (d,
J¼11.5 Hz, 1H), 4.52 (d, J¼11.5 Hz, 1H), 4.17e4.08 (m, 2H), 3.75e3.69
(m, 2H), 3.64e3.55 (m, 3H), 2.27 (t, J¼6.0 Hz,1H), 1.78e1.71 (m,1H),
1.61e1.54 (m, 1H), 1.49e1.42 (m, 1H), 1.36e1.18 (m, 23H), 0.88 (t,
128.36, 128.2, 127.8, 127.7, 127.65, 127.5, 127.4, 99.4, 84.4, 80.3, 79.6,
79.0, 76.6, 75.1, 74.6, 73.5, 73.4, 73.2, 71.7, 70.4, 69.6, 63.2, 31.9, 30.6,
29.9, 29.7, 29.4, 25.9, 22.7, 14.1; ESI-HRMS [MþH]þ calcd for
þ
C66H85O9
1021.6194, found 1021.6191. For 16b:
1H NMR
(500 MHz, CDCl3)
d
7.35e7.23 (m, 30H), 4.94 (d, J¼12.0 Hz, 1H), 4.87
J¼7.0 Hz, 3H); 13C NMR (125 MHz, CDCl3)
d
138.5, 138.4, 134.9,
(d, J¼11.0 Hz, 1H), 4.74 (t, J¼11.5 Hz, 2H), 4.72 (d, J¼8.0 Hz, 1H),
4.70e4.58 (m, 4H), 4.53 (d, J¼11.0 Hz, 1H), 4.43e4.35 (m, 3H), 4.09
(ddd, J¼11.0, 6.5, 2.5 Hz, 1H), 3.96 (dd, J¼6.3, 9.5 Hz, 1H), 3.90 (d,
J¼2.5 Hz, 1H), 3.81 (dd, J¼7.8, 9.5 Hz, 1H), 3.69e3.65 (m, 2H),
3.59e3.50 (m, 5H), 3.23 (d, J¼5.0 Hz, 1H), 1.63e1.38 (m, 2H),
1.42e1.16 (m, 24H), 0.88 (t, J¼7.0 Hz, 3H); 13C NMR (125 MHz,
128.3, 128.0, 127.9, 127.6, 127.58, 117.0, 80.3, 80.1, 79.7, 74.0, 72.1,
72.0, 61.9, 31.9, 30.4, 29.7, 29.67, 29.63, 29.3, 25.8, 22.7, 14.1; ESI-
HRMS [MþNH4]þ calcd for C35H58NO4þ 556.4360, found 556.4358.
3.5. (2R,3S,4R)-3,4-Di-O-benzyl-1,2,3,4-octadecanetetrol (14)
CDCl3)
d 138.7, 138.6, 138.5, 138.3, 138.2, 137.8, 128.4, 128.3, 128.2,
A mixture of compound 13 (560 mg, 1.04 mmol) and PdCl2
(36.9 mg, 0.208 mmol) in dry MeOH (10 mL) was stirred overnight.
The reaction was then diluted with MeOH (10 mL), filtered through
Celite and concentrated under reduced pressure. The crude residue
was purified by column chromatography on silica gel (petroleum
ether/EtOAc 1:1) to give compound 14 as white waxy solids
128.16, 128.1, 128.07, 127.9, 127.87, 127.8, 127.7, 127.6, 127.5, 104.1,
82.2, 79.9, 79.5, 78.9, 75.2, 74.6, 73.6, 73.5, 73.3, 73.0, 72.9, 70.9,
70.0, 68.6, 31.9, 31.2, 29.7, 29.67, 29.63, 29.4, 25.7, 22.7, 14.1; ESI-
þ
HRMS [MþNH4]þ calcd for C66H88NO9
1038.6454, found
7.35e7.20 (m,
1038.6459. For 17
b:
1H NMR (500 MHz, CDCl3)
d
30H), 4.94 (d, J¼11.5 Hz, 1H), 4.88 (d, J¼11.0 Hz, 1H), 4.80 (d,
J¼11.0 Hz, 1H), 4.74e4.67 (m, 3H), 4.62e4.56 (m, 4H), 4.46 (d,
J¼11.5 Hz, 1H), 4.31 (dd, J¼18.0, 11.5 Hz, 2H), 4.00e3.96 (m, 1H),
3.92e3.88 (m, 2H), 3.71e3.52 (m, 6H), 3.49 (dd, J¼7.0, 6.0 Hz, 1H),
3.38 (dd, J¼8.8, 5.5 Hz, 1H), 3.03 (dd, J¼9.0, 4.0 Hz, 1H), 1.68e1.60
(m, 2H), 1.48e1.40 (m, 2H), 1.34e1.18 (m, 22H), 0.88 (t, J¼7.0 Hz,
(436 mg, 84%). 1H NMR (500 MHz, CDCl3)
d 7.37e7.25 (m, 10H), 4.74
(d, J¼11.5 Hz, 1H), 4.66 (d, J¼11.5 Hz, 1H), 4.59 (d, J¼11.5 Hz, 1H),
4.55 (d, J¼11.5 Hz, 1H), 3.91e3.87 (m, 1H), 3.70e3.64 (m, 3H), 3.54
(t, J¼4.0 Hz, 1H), 3.26 (d, J¼4.0 Hz, 1H), 2.16 (br s, 1H), 1.73e1.65 (m,
2H), 1.60e1.54 (m, 1H), 1.45e1.38 (m, 1H), 1.36e1.20 (m, 22H), 0.88
(t, J¼7.0 Hz, 3H); 13C NMR (125 MHz, CDCl3)
d
138.0, 137.8, 128.5,
3H); 13C NMR (125 MHz, CDCl3)
d 138.84, 138.8, 138.6, 138.2, 138.0,
128.4,128.1,128.0,127.99,127.8, 79.7, 79.1, 73.3, 72.7, 71.2, 64.0, 31.9,
30.8, 29.7, 29.65, 29.59, 29.56, þ29.3, 25.5, 22.7, 14.1; ESI-HRMS
[MþNH4]þ calcd for C32H54NO4 883.5579, found 883.5540. The
spectroscopic data coincide with those reported in the literature.30
137.8, 128.5, 128.4, 128.37, 128.24, 128.22, 128.2, 127.8, 127.78, 127.6,
127.54, 127.49, 127.4, 104.0, 82.8, 82.1, 80.0, 79.7, 78.8, 76.5, 75.7,
74.6, 73.8, 73.5, 73.4, 73.2, 72.6, 71.6, 68.4, 63.3, 34.1, 31.9, 30.4, 29.9,
29.7, 29.6, 29.4, 25.6, 22.7, 14.1; ESI-HRMS [MþNH4]þ calcd for
þ
C
66H88NO9 1038.6454, found 1038.6446.
3.6. 1-O-(20,30,40,60-Tetra-O-benzyl-
di-O-benzyl- -arabino-1,2,3,4-octadecanetetrol (16
(20,30,40,60-tetra-O-benzyl-
-galactopyranosyl)-3,4-di-O-ben-
zyl- -arabino-1,2,3,4-octadecanetetrol (17
a
-D
-galactopyranosyl)-3,4-
D
a
) and 2-O-
3.7. 1-O-(20,30,40,60-Tetra-O-benzyl-
di-O-benzyl- -ribo-1,2,3,4-octadecanetetrol (18)
a-D-galactopyranosyl)-3,4-
a-
D
D
D
a)
ꢀ
To a mixture of 16a (80.0 mg, 0.078 mmol) and 4 A molecular
To a mixture of donor 1521 (58.0 mg, 0.09 mmol), acceptor 14
sieves (300 mg) in CH2Cl2 (6 mL) was added PCC (52.0 mg,
0.24 mmol) at 0 ꢀC. After stirred at room temperature for 3 h, the
reaction mixture was diluted with CH2Cl2 and then filtered through
Celite. The filtrate was concentrated, and the residue was purified
by column chromatography on silica gel (petroleum ether/EtOAc
5:1) to give the crude corresponding aldehyde, which was dis-
solved in MeOH (5 mL). NaBH4 (9.0 mg, 0.24 mmol) was added to
the solution at 0 ꢀC. The mixture was allowed to warm to room
temperature and stirred for 2 h. The solvent was evaporated and
the resulting residue was purified by column chromatography on
ꢀ
(50.0 mg, 0.1 mmol), and 4 A molecular sieves (400 mg) in CH2Cl2
(4 mL) was added NIS (25.6 mg, 0.108 mmol) at room temperature
under Ar. The reaction mixture was stirred and TfOH (11 mL, 0.5 M in
Et2O, 0.0054 mmol) was added. After 2 h, the reaction was
quenched with Et3N (0.3 mL). The residue was diluted with CH2Cl2
and then filtered through Celite. The filtrate was concentrated,
washed with H2O, saturated aqueous Na2S2O3 solution and brine,
dried over Na2SO4, and concentrated in vacuo. The residue was
purified by column chromatography on silica gel (petroleum ether/
EtOAc 4:1 to 2:1) to give compound 16
(10.0 mg,11%),16 (16.0 mg,18%), and 17 (8.0 mg, 9%) as syrup. For
16 7.35e7.23 (m, 30H), 4.92 (d,
1H NMR (500 MHz, CDCl3)
a
(39.0 mg, 43%), 17
a
silica gel (petroleum ether/EtOAc 5:1) to give 18 (48.0 mg) and 16
a
b
b
(30.0 mg) as yellow oil (98%). 1H NMR (500 MHz, CDCl3)
d
7.38e7.23
a
:
d
(m, 30H), 4.92 (d, J¼11.5 Hz, 1H), 4.85 (d, J¼3.5 Hz, 1H), 4.82 (d,
J¼12.0 Hz, 1H), 4.81 (d, J¼12.0 Hz, 1H), 4.74 (d, J¼11.5 Hz, 1H), 4.73
(d, J¼12.0 Hz, 1H), 4.68e4.54 (m, 4H), 4.47 (d, J¼11.5 Hz, 1H), 4.44
(d, J¼12.0 Hz, 1H), 4.37 (d, J¼12.0 Hz, 1H), 4.05e3.91 (m, 6H),
3.68e3.65 (m, 1H), 3.62 (dd, J¼6.8, 3.0 Hz, 1H), 3.57 (dd, J¼10.8,
8.0 Hz, 1H), 3.50e3.43 (m, 2H), 3.40 (br s, 1H), 1.68e1.63 (m, 2H),
1.45e1.42 (m, 2H), 1.31e1.18 (m, 22H), 0.88 (t, J¼7.0 Hz, 3H); 13C
J¼11.5 Hz, 1H), 4.87 (d, J¼4.0 Hz, 1H), 4.78 (t, J¼11.5 Hz, 2H),
4.71e4.60 (m, 4H), 4.56e4.48 (m, 3H), 4.45 (d, J¼12.0 Hz, 1H), 4.37
(d, J¼11.5 Hz, 1H), 4.06e4.00 (m, 3H), 3.96e3.92 (m, 2H), 3.78e3.73
(m, 1H), 3.66e3.63 (m, 1H), 3.60e3.57 (m, 2H), 3,52e3.49 (m, 2H),
3.23 (d, J¼5.0 Hz, 1H), 1.64e1.58 (m, 1H), 1.46e1.38 (m, 1H),
1.36e1.19 (m, 24H), 0.88 (t, J¼7.0 Hz, 3H); 13C NMR (125 MHz,
CDCl3)
d
138.74, 138.67, 138.6, 138.4, 138.3, 138.0, 128.35, 128.27,
NMR (125 MHz, CDCl3) d 138.8, 138.63, 138.58, 138.3, 137.8, 128.4,
128.2, 128.0, 127.9, 127.8, 127.7, 127.6, 127.5, 127.4, 127.36, 98.3, 79.8,
79.5, 79.1, 76.5, 75.0, 74.8, 73.6, 73.44, 73.40, 72.9, 72.7, 69.8, 69.5,
128.3, 128.2, 128.0, 127.9, 127.8, 127.7, 127.6, 127.5, 127.4, 99.7, 80.4,
80.2, 79.2, 76.6, 74.9, 74.7, 73.7, 73.6, 73.5, 73.0, 72.6, 72.0, 70.6, 69.7,
69.1, 31.9, 29.9, 29.86, 29.7, 29.4, 25.8, 22.7, 14.1; ESI-HRMS
68.9, 31.9, 31.1, 29.8, 29.7, 29.4, 25.7, 22.7, 14.1; ESI-HRMS [MþH]þ
þ
þ
calcd for C66H85O9 1021.6194, found 1021.6172. For 17
a
: 1H NMR
[MþNa]þ calcd for C66H84NaO9 1043.6008, found 1043.6018.

M. Sun et al. / Tetrahedron 69 (2013) 7438e7447
7443
3.8. 1-O-(20,30,40,60-Tetra-O-benzyl-
a
-
D
-galactopyranosyl)-3,4-
30.1, 30.0, 29.9, 29.6, 29.5, 29.46, 26.9, 26.6, 26.3, 25.9, 22.8, 14.1;
þ
di-O-benzyl-2-O-(800-phenyloctyl)-
D
-ribo-1,2,3,4-
ESI-HRMS [MþH]þ calcd for C38H69O9 669.4942, found 669.4943.
octadecanetetrol (21)
3.11. 1-O-(
octadecanetetrol (5)
a-D D-ribo-1,2,3,4-
-Galactopyranosyl)-2-O-(80-octyl)-
KOH (9.4 mg, 0.132 mmol) was added to a solution of compound
18 (45.0 mg, 0.044 mmol) in dry toluene (2 mL). The mixture was
stirred for 10 min after which a solution of 1923 (22.2 mg,
0.062 mmol) in toluene (2 mL) was added to it. The resulting
mixture was refluxed at 110 ꢀC overnight and then concentrated in
vacuo. The residue was purified by column chromatography on
silica gel (petroleum ether/EtOAc 10:1) to give compound 21 as
The synthetic procedure was the same as that described in the
synthesis of compound 4 using Pd/C (10% on carbon, 20.0 mg) and
22 (29.9 mg, 0.0264 mmol) to afford 5 as a colorless oil (15.0 mg,
96%). 1H NMR (500 MHz, CD3OD)
d
4.84 (d, J¼4.5 Hz, 1H), 4.05 (dd,
J¼11.0, 3.5 Hz, 1H), 3.89e3.86 (m, 2H), 3.77e3.67 (m, 7H), 3.60 (dd,
J¼11.0, 4.0 Hz, 1H), 3.52 (m, 1H), 3.41 (dt, J¼9.5, 7.0 Hz, 1H),
1.64e1.52 (m, 4H), 1.37e1.28 (m, 34H), 0.90 (t, J¼7.0 Hz, 3H), 0.89 (t,
a yellow oil (45.0 mg, 85%). 1H NMR (500 MHz, CDCl3)
d 7.36e7.14
(m, 35H), 4.94 (d, J¼3.5 Hz, 1H), 4.93 (d, J¼11.5 Hz, 1H), 4.81e4.55
(m, 8H), 4.43 (d, J¼12.0 Hz, 1H), 4.42 (d, J¼11.5 Hz, 1H), 4.33 (d,
J¼12.0 Hz, 1H), 4.05 (dd, J¼9.5, 3.5 Hz, 1H), 3.99e3.95 (m, 4H), 3.75
(dd, J¼5.5, 4.0 Hz, 1H), 3.70e3.56 (m, 4H), 3.53 (dd, J¼9.3, 7.0 Hz,
1H), 3.45 (q, J¼5.0 Hz, 1H), 3.35 (dt, J¼11.3, 6.5 Hz, 1H), 2.57 (t,
J¼7.5 Hz, 2H), 1.68e1.61 (m, 1H), 1.56e1.19 (m, 37H), 0.88 (t,
J¼7.5 Hz, 3H); 13C NMR (125 MHz, CD3OD)
d 100.8, 80.5, 74.6, 72.9,
72.4, 71.5, 71.2, 71.0, 70.3, 67.1, 62.8, 33.1, 32.8, 31.2, 30.9, 30.81,
30.76, 30.67, 30.51, 30.47, 27.43, 27.0þ, 23.8, 23.7, 14.5, 14.4; ESI-
HRMS [MþNa]þ calcd for C32H64NaO9 615.4443, found 615.4458.
J¼7.0 Hz, 3H); 13C NMR (125 MHz, CDCl3)
d
142.8, 138.9, 138.84,
3.12. 2-O-(20,30,40,60-Tetra-O-benzyl-
a
-
D
-galactopyranosyl)-
-arabino-1,2,3,4-
138.78, 138.1, 128.4, 128.31, 128.28, 128.2, 128.17, 127.9, 127.8, 127.7,
127.6, 127.5, 127.4, 127.3, 125.5, 98.1, 79.7, 79.2, 79.0, 78.9, 76.6, 75.0,
74.8, 73.7, 73.5, 72.9, 72.8, 71.8, 70.7, 69.2, 69.0, 68.0, 36.0, 31.9, 31.5,
30.2, 30.0, 29.9, 29.7, 29.6, 29.4þ, 26.3, 25.7, 22.7, 14.1; ESI-HRMS
[MþNa]þ calcd for C80H104NaO9 1231.7573, found 1231.7569.
3,4-di-O-benzyl-1-O-(800-phenyloctyl)-
D
octadecanetetrol (23)
The synthetic procedure was the same as that described in the
synthesis of compound 21 using KOH (8 mg, 0.115 mmol), 17
(39.0 mg, 0.038 mmol), and 19 (18.0 mg, 0.05 mmol) to afford 23 as
a yellow oil (39.0 mg, 85%). 1H NMR (500 MHz, CDCl3)
7.35e7.14
a
3.9. 1-O-(20,30,40,60-Tetra-O-benzyl-
di-O-benzyl-2-O-(800-octyl)-
-ribo-1,2,3,4-octadecanetetrol (22)
a
-
D
-galactopyranosyl)-3,4-
d
D
(m, 35H), 5.13 (d, J¼3.0 Hz, 1H), 4.91 (d, J¼11.5 Hz, 1H), 4.79 (d,
J¼12.0 Hz, 1H), 4.74e4.68 (m, 4H), 4.60 (d, J¼12.5 Hz, 1H), 4.55 (d,
J¼11.5 Hz, 1H), 4.50e4.43 (m, 2H), 4.39 (d, J¼12.0 Hz, 1H), 4.33 (d,
J¼11.5 Hz, 1H), 4.17 (t, J¼6.5 Hz, 1H), 4.05e3.98 (m, 3H), 3.93 (dd,
J¼10.5, 5.5 Hz, 1H), 3.85 (t, J¼4.5 Hz, 1H), 3.72e3.68 (m, 1H),
3.64e3.48 (m, 4H), 3.33e3.25 (m, 2H), 2.57 (t, J¼7.5 Hz, 2H),
1.72e1.62 (m, 1H), 1.52e1.18 (m, 37H), 0.88 (t, J¼7.0 Hz, 3H); 13C
The synthetic procedure was the same as that described in the
synthesis of compound 21 using KOH (6.4 mg, 0.094 mmol), 18
(32.0 mg, 0.031 mmol), and 2024 (13.3 mg, 0.047 mmol) to afford 22
as a colorless oil (23.3 mg, 65%). 1H NMR (400 MHz, CDCl3)
d
7.36e7.21 (m, 30H), 4.94 (d, J¼3.2 Hz, 1H), 4.93 (d, J¼12.0 Hz, 1H),
4.80 (d, J¼12.0 Hz,1H), 4.76 (d, J¼12.0 Hz,1H), 4.73 (d, J¼11.2 Hz,1H),
4.68e4.63 (m, 3H), 4.60 (d, J¼11.6 Hz, 1H), 4.56 (d, J¼11.2 Hz, 1H),
4.43 (d, J¼11.6 Hz,1H), 4.42 (d, J¼12.0 Hz,1H), 4.33 (d, J¼11.6 Hz,1H),
4.05 (dd, J¼9.4, 3.4 Hz, 1H), 4.00e3.95 (m, 4H), 3.75 (dd, J¼5.8,
3.8 Hz,1H), 3.69e3.57 (m, 4H), 3.53 (dd, J¼11.0, 7.4 Hz,1H), 3.45 (dd,
J¼9.2, 6.0 Hz, 1H), 3.34 (dt, J¼8.8, 6.8 Hz, 1H), 1.69e1.61 (m, 1H),
1.53e1.42 (m, 3H),1.33e1.23 (m, 34H), 0.88 (t, J¼6.8 Hz, 3H), 0.87 (t,
NMR (125 MHz, CDCl3) d 142.8,139.3,139.0,138.8,138.7,138.1,128.4,
128.31, 128.28, 128.2, 128.1, 128.09, 127.9, 127.74, 127.7, 127.6, 127.4,
127.3, 127.2, 127.1, 125.5, 99.2, 79.6, 79.2, 79.0, 78.4, 76.3, 75.1, 74.7,
73.6, 73.5, 73.2, 72.8, 71.4, 71.0, 70.4, 69.4, 69.0, 36.0, 31.9, 31.5, 30.4,
30.3, 30.0, 29.7, 29.54, 29.49, 29.4, þ29.3, 26.2, 25.7, 22.7, 14.1; ESI-
HRMS [MþH]þ calcd for C80H105O9 1209.7759, found 1209.7750.
J¼7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3)
d
138.92, 138.83, 138.80,
3.13. 2-O-(
bino-1,2,3,4-octadecanetetrol (8)
a-D D-ara-
-Galactopyranosyl)-1-O-(80-phenyloctyl)-
138.76, 138.05, 128.31, 128.27, 128.20, 128.16, 127.85, 127.81, 127.75,
127.61,127.51,127.47,127.37,127.32, 98.04, 79.71, 79.08, 78.98, 78.88,
76.63, 75.03, 74.75, 73.68, 73.45, 72.95, 72.80, 71.81, 70.70, 69.24,
68.95, 67.93, 31.91, 31.89, 30.19, 29.99, 29.87, 29.72, 29.66, 29.56,
The synthetic procedure was the same as that described in the
synthesis of compound 4 using Pd/C (10% on carbon, 10 mg) and 23
(16.0 mg, 0.013 mmol) to afford 8 as a colorless oil (8.6 mg, 97%). 1H
29.35, 26.34, 25.70, 22.68, 14.10; ESI-HRMS [MþH]þ calcd for
þ
C
74H101O9 1133.7440, found 1133.7487.
NMR (500 MHz, CDCl3/CD3OD¼1:1)
d 7.29e7.25 (m, 2H), 7.20e7.16
(m, 3H), 5.07 (d, J¼4.0 Hz, 1H), 4.00e3.94 (m, 3H), 3.81e3.64 (m,
7H), 3.55 (dd, J¼7.0, 2.0 Hz,1H), 3.47e3.44 (m, 2H), 2.60 (t, J¼7.5 Hz,
2H), 1.72e1.50 (m, 7H), 1.50e1.40 (m, 2H), 1.40e1.14 (m, 29H), 0.89
3.10. 1-O-(
1,2,3,4-octadecanetetrol (4)
a-D D-ribo-
-Galactopyranosyl)-2-O-(80-phenyloctyl)-
(t, J¼7.0 Hz, 3H); 13C NMR (125 MHz, CDCl3/CD3OD¼1:1)
d 143.0,
Pd/C (10% on carbon, 15 mg) was added to a solution of com-
pound 21 (29.0 mg, 0.024 mmol) in MeOH/CH2Cl2 (5 mL, 2:3) at
room temperature. The mixture was stirred under H2 (3 atm) for
12 h and then filtered through Celite. The filter cake was rinsed with
MeOH and CH2Cl2. The filtrate was concentrated, and the residue
was purified by flash column chromatography on silica gel (CH2Cl2/
MeOH 10:1) to provide 4 as a colorless oil (15.6 mg, 98%). 1H NMR
128.6, 128.4, 125.7, 101.1, 78.0, 74.0, 72.1, 71.9, 71.0, 70.7, 70.3, 70.2,
69.4, 62.2, 36.1, 33.8, 33.7, 32.1, 31.7, 30.0, 29.9, 29.8, 29.64, 29.59,
29.4, 26.6, 26.3, 25.9, 22.8, 14.1; ESI-HRMS [MþNa]þ calcd for
þ
C
38H68NaO9 691.4761, found 691.4758.
3.14. 2-O-(20,30,40,60-Tetra-O-benzyl-
a-D-galactopyranosyl)-
3,4-di-O-benzyl-1-O-(800-hexacosanoyloxy)-
D-arabino-1,2,3,4-
(500 MHz, CDCl3/CD3OD¼1:1)
d
7.27 (dd, J¼8.3, 7.0 Hz, 2H),
octadecanetetrol (24)
7.20e7.16 (m, 3H), 4.89 (d, J¼3.5 Hz, 1H), 4.03 (dd, J¼11.0, 4.0 Hz,
1H), 3.98 (d, J¼2.0 Hz, 1H), 3.87 (t, J¼5.5 Hz, 1H), 3.83e3.73 (m, 4H),
3.72e3.61 (m, 4H), 3.52e3.47 (m, 1H), 3.42e3.37 (m, 1H), 2.60 (t,
J¼7.5 Hz, 2H), 1.72e1.66 (m, 1H), 1.64e1.50 (m, 6H), 1.48e1.39 (m,
2H), 1.38e1.15 (m, 29H), 0.88 (t, J¼7.0 Hz, 3H); 13C NMR (125 MHz,
A mixture of compound 17
a (26.6 mg, 0.026 mmol), n-hex-
acosanoic acid (46.5 mg, 0.12 mmol), EDAC (100 mg, 0.52 mmol),
and DMAP (64.3 mg, 0.52 mmol) in dry CH2Cl2 (8 mL) was stirred
for 3 days at room temperature and then diluted with CHCl3. The
solution was washed with H2O and brine, dried over MgSO4, and
filtered. The filtrate was concentrated in vacuo. The residue was
CDCl3/CD3OD¼1:1)
d 143.0,128.5, 128.4, 125.7, 99.4, 79.6, 72.9, 72.4,
70.5, 70.46, 70.2, 70.19, 69.3, 65.7, 62.2, 36.1, 33.7, 32.2, 32.1, 31.7,

7444
M. Sun et al. / Tetrahedron 69 (2013) 7438e7447
purified by column chromatography on silica gel (petroleum ether/
EtOAc 15:1) to give 24 as a colorless oil (20.0 mg, 55%). 1H NMR
(238.1 mg, 88%). 1H NMR (400 MHz, CDCl3)
d 3.92e3.88 (m, 1H),
3.75 (dd, J¼6.0, 2.4 Hz, 1H), 3.73e3.70 (m, 3H), 2.39 (t, J¼6.0 Hz, 1H,
OH), 1.54e1.42 (m, 1H), 1.42e1.26 (m, 25H), 0.91 (s, 18H), 0.88 (t,
J¼7.2 Hz, 3H), 0.13 (s, 3H), 0.11 (s, 6H), 0.09 (s, 3H); 13C NMR
(500 MHz, CDCl3)
d
7.34e7.19 (m, 30H), 5.12 (d, J¼3.5 Hz, 1H), 4.90
(d, J¼11.0 Hz, 1H), 4.78e4.65 (m, 5H), 4.59 (d, J¼12.0 Hz, 1H), 4.53
(d, J¼11.5 Hz, 1H), 4.49 (d, J¼11.5 Hz, 1H), 4.48 (d, J¼11.5 Hz, 1H),
4.39 (d, J¼11.5 Hz, 1H), 4.35 (d, J¼11.5 Hz, 1H), 4.33 (dd, J¼11.5,
6.0 Hz, 1H), 4.24 (dd, J¼12.0, 6.0 Hz, 1H), 4.13 (t, J¼7.0 Hz, 1H),
4.05e3.99 (m, 3H), 3.98 (dd, J¼10.5, 2.5 Hz, 1H), 3.78 (t, J¼5.0 Hz,
1H), 3.69 (ddd, J¼5.0, 4.5, 4.0 Hz, 1H), 3.58 (t, J¼8.0 Hz, 1H), 3.49
(dd, J¼9.0, 5.5 Hz, 1H), 2.25 (t, J¼8.0 Hz, 2H), 1.71e1.62 (m, 2H),
1.54e1.50 (m, 2H), 1.42e1.21 (m, 68H), 0.88 (t, J¼7.0 Hz, 6H); 13C
(100 MHz, CDCl3) d 76.0, 75.5, 64.7, 62.1, 33.8, 31.9, 29.8, 29.7, 29.65,
29.62, 29.56, 29.55, 29.4, 25.99, 25.97, 25.5, 22.7, 18.21, 18.18, 14.1,
ꢁ4.0, ꢁ4.2, ꢁ4.5, ꢁ4.8; ESI-HRMS [MþNa]þ calcd for
þ
C
30H65N3NaO3Si2 594.4457, found 594.4445.
3.17. (2R,3R,4R)-1-O-(20,30,40,60-Tetra-O-benzyl-
actopyranosyl)-2-azido-3,4-di-tert-butyldimethylsilyloxy-
octadecane (27
a-D-gal-
NMR (125 MHz, CDCl3)
d
173.4, 138.7, 138.6, 138.0, 128.33, 128.30,
a)
128.2, 128.14, 128.11, 127.8, 127.7, 127.6, 127.5, 127.3, 99.1, 79.5, 79.2,
79.1, 76.7, 76.1, 74.9, 74.8, 73.5, 73.4, 73.3, 72.7, 71.5, 69.6, 68.6, 64.1,
34.1, 31.9, 30.5, 29.9, 29.7, 29.5, 29.4, 29.2, 25.8, 24.9, 22.7, 14.1; ESI-
HRMS [MþH]þ calcd for C92H138NO10þ 1417.0315, found 1417.0295.
The synthetic procedure was the same as that described in the
synthesis of compound 16 using 15 (50.0 mg, 0.077 mmol), 26
(40.2 mg, 0.070 mmol), NIS (19.5 mg, 0.084 mmol), and TfOH
(8.4 L, 0.5 M in Et2O, 0.0042 mmol) to afford 27 (81.0 mg, 53%)
and its -anomer (41.2 mg, 27%) as colorless oil. For 27
1H NMR
(400 MHz, CDCl3)
7.38e7.24 (m, 20H), 4.94 (d, J¼11.2 Hz, 1H), 4.90
a
m
a
3.15. 2-O-(
a
-D
-Galactopyranosyl)-1-O-(800-hexacosanoyloxy)-
b
a:
D-arabino-1,2,3,4-octadecanetetrol (9)
d
(d, J¼3.6 Hz, 1H), 4.83 (d, J¼12.0 Hz, 1H), 4.78 (d, J¼12.0 Hz, 1H),
4.72 (m, 2H), 4.56 (d, J¼11.6 Hz, 1H), 4.45 (d, J¼12.0 Hz, 1H), 4.38 (d,
J¼11.6 Hz, 1H), 4.07e3.95 (m, 5H), 3.80e3.74 (m, 1H), 3.74e3.70 (m,
1H), 3.62 (dd, J¼5.2, 3.6 Hz, 1H), 3.57e3.53 (m, 2H), 3.46 (dd, J¼8.8,
5.6 Hz, 1H), 1.54e1.33 (m, 2H), 1.26 (m, 24H), 0.89e0.87 (m, 21H),
0.09 (s, 3H), 0.08 (s, 3H), 0.06 (s, 6H); 13C NMR (100 MHz, CDCl3)
A solution of compound 24 (38.8 mg, 0.028 mmol) in MeOH/
CH2Cl2 (6 mL, 1:1) containing Pd(OH)2/C (20%, 35.0 mg) was stirred
for 1 h at room temperature under hydrogen atmosphere (balloon).
The suspension was then filtered through a bed of Celite, and the
filter cake was washed with CH2Cl2/MeOH (5:1). The combined
filtrate was concentrated in vacuo, and the residue was purified by
column chromatography on silica gel (CH2Cl2/MeOH 10:1) to give 9
as white solids (23.0 mg, 97%). 1H NMR (500 MHz, CDCl3/CD3OD)
d
138.9, 138.82, 138.79, 138.0, 128.34, 128.27, 128.18, 128.15, 127.8,
127.6, 127.5, 127.44, 127.35, 99.0, 78.7, 76.4, 76.1, 75.2, 74.7, 74.6,
73.4, 73.2, 73.0, 69.6, 69.3, 68.7, 63.8, 33.0, 31.9, 29.8, 29.67, 29.65,
29.60, 29.4, 26.0, 23.2, 22.7, 18.24, 18.16, 14.1, ꢁ4.1, ꢁ4.5, ꢁ4.7; ESI-
d
5.06 (d, J¼4.0 Hz, 1H), 4.35 (dd, J¼11.0, 5.5 Hz, 1H), 4.22 (dd,
þ
J¼11.0, 7.0 Hz, 1H), 4.05 (m, 1H), 3.98 (d, J¼2.5 Hz, 1H), 3.91 (t,
J¼6.0 Hz, 1H), 3.89e3.72 (m, 4H), 3.68 (m, 1H), 3.44 (dd, J¼6.5,
2.0 Hz, 1H), 2.33 (t, J¼7.5 Hz, 2H), 1.67e1.43 (m, 4H), 1.42e1.22 (m,
70H), 0.88 (t, J¼7.0 Hz, 6H); 13C NMR (100 MHz, CDCl3/CD3OD)
HRMS [MþNH4]þ calcd for C64H103N4O8Si2 1111.7309, found
1111.7271. For its b d 7.37e7.23
-anomer: 1H NMR (400 MHz, CDCl3)
(m, 20H), 4.96 (d, J¼11.6 Hz, 1H), 4.94 (d, J¼11.2 Hz, 1H), 4.77e4.69
(m, 3H), 4.44 (d, J¼12.0 Hz, 1H), 4.40 (d, J¼11.2 Hz, 1H), 4.38 (d,
J¼7.6 Hz, 1H), 4.00 (dd, J¼10.8, 8.4 Hz, 1H), 3.91 (d, J¼2.4 Hz, 1H),
3.87e3.81 (m, 2H), 3.76e3.72 (m, 2H), 3.64e3.59 (m, 2H),
3.57e3.50 (m, 3H), 1.53e1.35 (m, 2H), 1.26 (m, 24H), 0.87e0.86 (m,
21H), 0.08 (s, 3H), 0.07 (s, 3H), 0.05 (s, 6H); 13C NMR (100 MHz,
d
174.4, 101.2, 77.5, 73.0, 72.0, 70.9, 70.1, 69.9, 69.1, 63.5, 61.9, 34.2,
33.8, 31.9, 29.8, 29.6, 29.4, 29.2þ, 25.9, 24.9, 22.7, 14.1; ESI-HRMS
[MþNa]þ calcd for C50H98NaO10 881.7043, found 881.7052.
3.16. (2R,3R,4R)-2-Azido-3,4-di-tert-butyldimethylsilyloxy-1-
CDCl3) d 138.8, 138.5, 137.9, 128.4, 128.3, 128.2, 128.11, 128.05,
octadecaneol (26)
127.96,127.9,127.8,127.5,127.40,127.36,103.9, 82.2, 79.5, 75.9, 75.2,
74.8, 74.5, 73.6, 73.5, 73.4, 73.0, 69.4, 68.6, 63.5, 33.1, 31.9, 29.8,
29.68, 29.65, 29.59, 29.4, 26.04, 26.03, 25.5, 22.7, 18.22, 18.15, 14.1,
To a stirred solution of compound 2519 (167.8 mg, 0.49 mmol) in
2,6-lutidine (5.5 mL) and CH2Cl2 (5.5 mL), TBSOTf (0.69 mL,
2.93 mmol) was added at 0 ꢀC. After stirring at room temperature
for 2.5 h, the reaction was quenched with MeOH (3 mL). The
resulting mixture was concentrated in vacuo, and the remaining
2,6-lutidine was removed azeotropically with toluene. The residue
was diluted with EtOAc, and washed with saturated aqueous
NaHCO3 solution and brine, dried over Na2SO4, and concentrated in
vacuo. The residue was purified by column chromatography on
silica gel (petroleum ether) to give the intermediate as a yellow oil
ꢁ4.00, ꢁ4.03, ꢁ4.5, ꢁ4.8; ESI-HRMS [MþNH4]þ calcd for
þ
C
64H103N4O8Si2 1111.7309, found 1111.7278.
3.18. (2R,3R,4R)-1-O-(20,30,40,60-Tetra-O-benzyl-
actopyranosyl)-2-azido-1,3,4-octadecanetriol (28)
a-D-gal-
To a stirred solution of compound 27
THF (4 mL), a solution of TBAF (1 M in THF, 460
a
(83.1 mg, 0.076 mmol) in
L, 0.46 mmol) was
m
added at 0 ꢀC. After stirring at room temperature overnight, the
reaction was quenched with water, and the resulting mixture was
extracted with EtOAc. The combined organic extract was succes-
sively washed with water and brine, dried over Na2SO4, and con-
centrated in vacuo. The residue was purified by column
chromatography on silica gel (petroleum ether/EtOAc 3:1) to give
28 as a colorless oil (52.7 mg, 80%). 1H NMR (500 MHz, CDCl3)
(325.5 mg, 97%). 1H NMR (400 MHz, CDCl3)
d
3.98 (dd, J¼10.4,
2.4 Hz, 1H), 3.75e3.66 (m, 2H), 3.61 (dd, J¼6.0, 2.8 Hz, 1H),
3.59e3.57 (m, 1H), 1.56e1.30 (m, 2H), 1.30e1.20 (m, 24H), 0.92 (s,
9H), 0.91 (s, 9H), 0.89 (s, 9H), 0.88 (t, J¼6.8 Hz, 3H); 13C NMR
(100 MHz, CDCl3)
d 75.8, 74.6, 65.4, 64.2, 32.9, 31.9, 29.9, 29.69,
29.67, 29.60, 29.4, 26.1, 26.0, 25.8, 25.3, 22.7, 18.3, 18.21, 18.20, 14.1,
ꢁ4.0, ꢁ4.1, ꢁ4.5, ꢁ4.7, ꢁ5.47, ꢁ5.51; ESI-HRMS [MþNa]þ calcd for
d
7.37e7.25 (m, 20H), 4.91 (d, J¼11.0 Hz, 1H), 4.89 (d, J¼12.0 Hz, 1H),
þ
C
36H79N3NaO3Si3 708.5330, found 708.5321.
4.78 (d, J¼3.5 Hz,1H), 4.76 (d, J¼11.5 Hz,1H), 4.72 (d, J¼12.0 Hz,1H),
4.66 (d, J¼12.0 Hz, 1H), 4.55 (d, J¼11.0 Hz, 1H), 4.49 (d, J¼12.0 Hz,
1H), 4.42 (d, J¼12.0 Hz, 1H), 4.16 (dd, J¼10.5, 3.5 Hz, 1H), 4.05 (dd,
J¼10.0, 3.5 Hz, 1H), 3.99 (t, J¼7.0 Hz, 1H), 3.95e3.93 (m, 1H), 3.92
(dd, J¼10.0, 2.5 Hz, 1H), 3.81 (dd, J¼10.5, 3.5 Hz, 1H), 3.74 (dd, J¼6.5,
5.5 Hz, 1H), 3.62e3.58 (m, 1H), 3.55e3.48 (m, 2H), 3.46 (dt, J¼5.0,
4.0 Hz, 1H), 3.34 (d, J¼7.0 Hz, 1H), 2.24 (d, J¼5.0 Hz, 1H), 1.54e1.46
(m, 2H), 1.40e1.26 (m, 24H), 0.88 (t, J¼7.0 Hz, 3H); 13C NMR
To a stirred solution of above intermediate (325.5, 0.48 mmol) in
THF (15 mL), 10% aqueous trifluoroacetic acid (v/v, 3 mL) was added
dropwise at 0 ꢀC and the mixture was stirred overnight. The re-
action was then quenched with 15% aqueous NaOH solution, di-
luted with EtOAc, washed with saturated aqueous NaHCO3 solution
and brine, dried over Na2SO4, and concentrated in vacuo. The res-
idue was purified by column chromatography on silica gel (petro-
leum ether/EtOAc 30:1 to 20:1) to give 26 as a colorless oil
(125 MHz, CDCl3) d 138.5, 138.3, 137.92, 137.87, 128.5, 128.4, 128.24,

M. Sun et al. / Tetrahedron 69 (2013) 7438e7447
7445
128.18, 128.1, 127.96, 127.80, 127.7, 127.62, 127.59, 99.2, 79.2, 75.9,
75.2, 74.8, 74.7, 74.2, 73.4, 72.9, 72.8, 70.1, 69.1, 68.9, 60.0, 32.6, 31.9,
30 as a yellow oil (159.0 mg, 80%). 1H NMR (300 MHz, CDCl3)
7.38e7.25 (m, 10H), 4.73e4.54 (m, 4H), 3.92e3.86 (m, 1H),
3.83e3.75 (m, 1H), 3.72e3.61 (m, 3H), 2.53 (t, J¼6.0 Hz, 1H),
1.70e1.50 (m, 2H), 1.45e1.18 (m, 24H), 0.88 (t, J¼7.0 Hz, 3H). The
spectroscopic data coincide with those reported in the literature.31
d
29.7, 29.4, 25.8, 22.7, 14.1; ESI-HRMS [MþNH4]þ calcd for
þ
C
52H75O8N4 883.5579, found 883.5540.
3.19. (2R,3R,4R)-1-O-(20,30,40,60-Tetra-O-benzyl-
a-D-gal-
actopyranosyl)-2-(800-phenyloctylamino)-1,3,4-octadecane-
triol (29)
3.22. (2S,3S,4R)-2-Hexacosylamino-3,4-di-O-benzyl-1,3,4-
octadecanetriol (31)
To a mixture of compound 28 (38.0 mg, 0.044 mmol) and
NiCl2$6H2O (10.7 mg, 0.044 mmol) in MeOH (5 mL), NaBH4 (5.0 mg,
0.132 mmol) was added at 0 ꢀC. The mixture was allowed to warm
to room temperature and stirred for 3 h. The solvent was evapo-
rated and the residue was dissolved in CH2Cl2 with several drops of
ammonia. The organic layer was washed with H2O and brine, dried
over Na2SO4, and concentrated in vacuo. The resulting residue
was dissolved in MeOH (3 mL), after which the aldehyde derived
from the treatment of PCC with 8-phenyloctan-1-ol (9.0 mg,
Triphenylphosphine (237 mg, 0.905 mmol) was added to a stir-
red solution of azide 30 (315.5 mg, 0.603 mmol) in dry THF (8 mL)
and the mixture was refluxed for 30 min before H2O (2 mL) was
added. After further stirring for 4 h, the solvent was removed. The
residue was dissolved in dry CH2Cl2 (10 mL) and treated with cer-
otic acid (222 mg, 0.548 mmol), HBTU (250 mg, 0.658 mmol), and
DIPEA (110.5 mL, 81.8 mg, 0.658 mmol) under Ar. After the mixture
was stirred overnight at room temperature, the solvent was evap-
orated. The resulting residue was purified by column chromatog-
raphy on silica gel (petroleum ether/EtOAc 2:1) to afford 31 as
0.044 mmol) and acetic acid (10.1 mL, 0.176 mmol) were added. The
reaction mixture was stirred for 30 min at room temperature. So-
dium cyanoborohydride (8.7 mg, 0.132 mmol) was added to the
resulting solution, and the mixture was stirred overnight at room
temperature. Saturated aqueous NaHCO3 was added to the result-
ing mixture and the aqueous layer was extracted twice with EtOAc.
The organic layer was washed with saturated aqueous NaHCO3 and
brine, dried over Na2SO4, and concentrated in vacuo. The resulting
residue was purified by column chromatography on silica gel (pe-
troleum ether/EtOAc/Et3N 1:1:0.02 to 1:1.5:0.02) to afford 29 as an
oil (23.0 mg, 51% for two steps). 1H NMR (500 MHz, CDCl3)
white solids (470.0 mg, 98%). 1H NMR (500 MHz, CDCl3)
d 7.39e7.26
(m, 10H), 6.03 (d, J¼8.5 Hz, 1H), 4.72 (d, J¼11.5 Hz, 1H), 4.64 (dd,
J¼25.3, 11.5 Hz, 2H), 4.45 (d, J¼11.5 Hz, 1H), 4.16e4.12 (m, 1H), 4.00
(d, J¼6.5 Hz, 1H), 3.72e3.67 (m, 2H), 3.63e3.58 (m, 1H), 3.06 (br s,
1H), 2.05e1.94 (m, 2H), 1.73e1.67 (m, 1H), 1.64e1.56 (m, 1H),
1.54e1.49 (m, 2H), 1.48e1.18 (m, 68H), 0.88 (t, J¼7.0 Hz, 6H). The
spectroscopic data coincide with those reported in the literature.32
3.23. (2R,3S,4R)-2-Hexacosylamino-3,4-di-O-benzyl-octade-
canoic acid (32)
d
7.38e7.15 (m, 25H), 4.93 (d, J¼11.5 Hz, 1H), 4.86 (d, J¼12.0 Hz, 1H),
4.78 (d, J¼11.5 Hz, 1H), 4.77 (d, J¼3.5 Hz, 1H), 4.74 (d, J¼11.5 Hz, 1H),
4.65 (d, J¼12.0 Hz, 1H), 4.56 (d, J¼11.0 Hz, 1H), 4.47 (d, J¼11.5 Hz,
1H), 4.39 (d, J¼12.0 Hz, 1H), 4.04 (dd, J¼10.0, 3.5 Hz, 1H), 3.98 (dd,
J¼10.0, 3.5 Hz, 1H), 3.95 (m, 1H), 3.91 (t, J¼6.5 Hz, 1H), 3.86 (dd,
J¼10.0, 2.5 Hz, 1H), 3.58e3.56 (m, 2H), 3.53e3.49 (m, 2H), 3.35 (t,
J¼7.5 Hz,1H), 2.81 (m, 1H), 2.70e2.66 (m, 1H), 2.58 (t, J¼7.5 Hz, 2H),
2.52e2.46 (m, 1H), 1.69e1.51 (m, 4H), 1.43e1.21 (m, 36H), 0.88 (t,
Method A. To a stirred solution of alcohol 31 (81.0 mg,
0.093 mmol) in CH2Cl2 (8 mL) was added sequentially TEMPO
(44.3 mg, 0.278 mmol) and DIAB (304 mg, 0.93 mmol). After 72 h,
the solvent was removed and the residue was purified by column
chromatography on silica gel (petroleum ether/EtOAc/HOAc
2:1:0.03) to give compound 32 as white solids (66.0 mg, 81%).
Method B. To a stirred solution of alcohol 31 (65.0 mg,
0.074 mmol) in CH2Cl2 (2 mL) was added TEMPO (5 mg, 0.03 mmol)
followed by iodobenzene diacetate (97 mg, 0.30 mmol). After 12 h,
the reaction mixture was then diluted with CH2Cl2 and washed with
saturated aqueous NaHCO3 solution and brine, dried over Na2SO4,
and concentrated in vacuo. The crude product was dissolved in
CH2Cl2 (5 mL) and treated with a solution of NaClO2 (211 mg,
1.86 mmol) and NaH2PO4$2H2O (20 mg, 0.027 mmol) in H2O (2 mL)
with several drops of Bu4NCl. After 0.5 h, the reaction mixture was
acidified with 1 N HCl and then diluted with CH2Cl2. The organic
phase was washed with H2O, dried over Na2SO4, and concentrated
in vacuo. The residue was purified by column chromatography on
silica gel (petroleum ether/EtOAc/HOAc 2:1:0.03) to give 32 as
J¼7.0 Hz, 3H); 13C NMR (100 MHz, CDCl3)
d 142.8, 138.5, 138.4,
138.0, 137.8, 128.5, 128.42, 128.39, 128.36, 128.24, 128.21, 128.16,
128.0,127.8, 127.6,127.4, 125.6,125.5, 99.1, 79.1, 76.8, 76.3, 74.8, 74.7,
74.1, 73.5, 72.8, 71.5, 70.2, 69.0, 66.5, 60.8, 46.7, 35.9, 34.4, 31.9, 31.4,
29.9, 29.70, 29.65, 29.4, 29.2, 27.0, 25.5, 22.7, 14.1; ESI-HRMS
þ
[MþH]þ calcd for C66H94N1O8 1028.6974, found 1028.6961.
3.20. (2R,3R,4R)-1-O-(a-D
-Galactopyranosyl)-2-(800-phenyl-
octylamino)-1,3,4-octadecanetriol (6)
The synthetic procedure was the same as that described in the
synthesis of compound 9 using 29 (12.0 mg, 0.012 mmol) and
Pd(OH)2/C (20%, 10.0 mg) to afford 6 as a colorless oil (6.1 mg, 78%).
white solids (59.0 mg, 90%). 1H NMR (500 MHz, CDCl3)
d 7.36e7.25
1H NMR (500 MHz, CDCl3/CD3OD)
d
7.27 (t, J¼8.0 Hz, 2H), 7.18e1.16
(m, 10H), 6.47 (d, J¼6.5 Hz, 1H), 4.80 (d, J¼6.0 Hz, 1H), 4.70 (dd,
J¼19.8, 11.5 Hz, 2H), 4.52 (dd, J¼18.3, 12.0 Hz, 2H), 3.82e3.80 (m,
1H), 3.78e3.72 (m, 1H), 2.08e1.97 (m, 2H), 1.89e1.84 (m, 1H),
1.75e1.69 (m, 2H), 1.54e1.46 (m, 2H), 1.40e1.18 (m, 67H), 0.88 (t,
(m, 3H), 4.91 (d, J¼4.0 Hz, 1H), 4.10 (dd, J¼11.5, 3.0 Hz, 1H), 3.93 (d,
J¼3.0 Hz, 1H), 3.86e3.77 (m, 8H), 3.71 (dd, J¼10.5, 7.5 Hz, 2H), 3.64
(dd, J¼9.0, 4.5 Hz, 1H), 3.47 (t, J¼8.5 Hz, 1H), 3.41 (br, 1H), 2.96 (t,
J¼7.5 Hz, 2H), 2.60 (t, J¼8.0 Hz, 2H),1.84e1.80 (m, 2H),1.74e1.65 (m,
2H), 1.64e1.50 (m, 2H), 1.44e1.20 (m, 32H), 0.88 (t, J¼7.0 Hz, 3H);
J¼7.0 Hz, 6H); 13C NMR (125 MHz, CDCl3)
d 173.0, 170.0, 137.4, 135.8,
128.9, 128.71, 128.66, 128.5, 128.1, 81.2, 80.0, 73.5, 72.4, 53.8, 36.4,
31.9, 30.7, 29.7, 29.6, 29.5, 29.4, 29þ.2, 25.8, 25.5, 22.7,14.1; ESI-HRMS
[MþNa]þ calcd for C58H99NNaO5 912.7415, found 912.7416.
13C NMR (125 MHz, CDCl3/CD3OD)
d 142.6, 128.2, 128.0, 125.4, 99.3,
72.4, 71.0, 69.7, 69.5, 68.9, 63.1, 61.8, 60.0, 45.5, 37.2, 35.7, 34.2, 32.6,
31.7, 31.2, 29.5, 29.2, 29.0, 28.9, 27.8,þ26.5, 25.2, 22.5, 19.5, 13.8; ESI-
HRMS [MþH]þ calcd for C38H70NO8 668.5096, found 668.5074.
3.24. N-[30-O-(200,300-Di-O-benzyl-400,600-O-benzylidene-
a-D-gal-
actopyranosyl)propyl] (2R,3S,4R)-2-hexacosylamino-3,4-di-O-
3.21. (2S,3S,4R)-2-Azido-3,4-di-O-benzyl-1,3,4-
benzyl-octadecanamide (34)
octadecanetriol (30)
The glycosylation procedure was the same as that described
The synthetic procedure was the same as that described in the
synthesis of compound 13 using 25 (130.0 mg, 0.38 mmol) to afford
in the synthesis of compound 16
a
, using p-methylphenyl 2,3-di-O-
benzyl-4,6-O-benzylidine-1-thio-
b
-D
-galactopyranoside20 (219.0 mg,

7446
M. Sun et al. / Tetrahedron 69 (2013) 7438e7447
0.395 mmol), 3-phthalimino-propanol33 (81.0 mg, 0.395 mmol), NIS
(119.0 mg, 0.474 mmol), and TfOH (47.4 L, 0.5 M in Et2O,
0.0237 mmol) to afford the -anomeric coupling product (126.0 mg,
50%) as white solids. 1H NMR (500 MHz, CDCl3)
7.82 (dd, J¼5.8,
3.27. In vivo stimulation with synthetic compounds
m
a
Stock solutions of KRN7000 and synthetic compounds were
prepared in 100% DMSO at a concentration of 1 mg/mL. Before use,
the solutions were diluted with phosphate buffered saline (pH 7.4)
d
3.0 Hz, 2H), 7.70 (dd, J¼5.5, 3.0 Hz, 2H), 7.51 (dd, J¼7.8, 1.5 Hz, 2H),
7.41e7.23 (m, 13H), 5.48 (s, 1H), 4.91 (d, J¼4.0 Hz, 1H), 4.82 (d,
J¼12.0 Hz, 1H), 4.77 (d, J¼12.5 Hz, 1H), 4.69 (d, J¼12.0 Hz, 1H), 4.67 (d,
J¼12.0 Hz, 1H), 4.23e4.18 (m, 2H), 4.06e4.01 (m, 2H), 3.96 (dd,
J¼10.0, 3.5 Hz, 1H), 3.85e3.67 (m, 4H), 3.52 (dt, J¼10.0, 6.0 Hz, 1H),
to obtain a final concentration of 10
intraperitoneally with 5 g of compound or with diluted DMSO
alone. Sera were collected at two time points, and the levels of IFN-
(at 16 h) and IL-4 (at 2 h) were measured by a standard sandwich
mg/mL. Mice were injected
m
g
2.05e1.99 (m, 2H); 13C NMR (125 MHz, CDCl3)
d
168.4, 138.9, 138.8,
ELISA using purified capture and biotin-conjugated detection
monoclonal antibodies and standards. ELISAs were developed with
TMB substrate, followed by evaluation using a microplate reader.
137.9, 133.9, 132.1, 128.8, 128.3, 128.1, 127.9, 127.6, 127.56, 127.5, 126.4,
123.2, 101.1, 98.7, 76.1, 75.6, 74.8, 73.4, 72.2, 69.5, 66.2, 62.8, 35.5, 28.7;
þ
ESI-TOF-MS [MþH]þ calcd for C38H38NO8
636, found 636;
[MþNH4]þ calcd for C38H41N2O8þ 653, found 653; [MþNa]þ calcd for
Acknowledgements
C
38H37NNaO8þ 658, found 658; [MþK]þ calcd for C38H37KNO8þ 674,
found 674; Anal. Calcd for C38H37NO8: C, 71.80; H, 5.87; N, 2.20.
Found: C, 71.71; H, 5.89; N, 2.17.
This work was financially supported by the National Natural
Science Foundation of China (Grant No. 21232002) and a grant
(2012CB822100) from the Ministry of Science and Technology of
China.
A solution of above glycosylation product (112.0 mg, 0.039 mol)
in aminomethane/MeOH (2 mL/2 mL) was refluxed for 0.5 h. The
solvent was evaporated and the resulting residue was purified by
column chromatography on silica gel (petroleum ether/EtOAc/
ammonia 5:1:0.06) to give compound 33 as a yellow syrup
(79.0 mg, 89%), which was directly used for the next reaction.
The coupling procedure was the same as that described in
the synthesis of compound 31, using amine 33 (70.0 mg,
0.142 mmol), acid 32 (101.0 mg, 0.114 mmol), HBTU (51.8 mg,
Supplementary data
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.tet.2013.06.051.
References and notes
0.137 mmol), and DIPEA (23
m
L, 17.0 mg, 0.137 mmol) to afford 34 as
white waxy solids (110.0 mg, 71%). 1H NMR (500 MHz, CDCl3)
d
7.49
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1377.9962.
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NMR (500 MHz, CDCl3/CD3OD¼1:1)
d 4.98e4.92 (br m, 1H), 4.89 (d,
J¼4.0 Hz, 1H), 3.98 (d, J¼2.5 Hz, 1H), 3.97e3.94 (br m, 1H),
3.90e3.73 (m, 6H), 3.70e3.65 (m, 1H), 3.57e3.48 (m, 2H),
3.44e3.38 (m, 1H), 2.35 (t, J¼7.5 Hz, 2H), 1.90e1.81 (m, 2H),
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þ
C
53H105N2O10 929.7769, found 929.7733.
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