1
720
K. AKASAKA et al.
gel column chromatography. High-resolution mass
spectra were measured in the EI mode or FAB mode
by using 4-nitrobenzaldehyde as a matrix with a JMS
resulting residue was added to 10
(50 ml) and extracted with 60 ml of ether. After
drying with MgSO , the solvent was evaporated un-
der reduced pressure, and the residue was dissolved
in 0.5 ml of toluene. An aliquot (50 l) and 1-ethyl-3-
(3 -dimethylaminopropyl)carbodiimide hydrochlo-
ride (EDC, 5 mg) were added to the mixture of
(1 ,2 )- or (1 ,2 )-1 (2 mg) and 4-dime-
thylaminopyridine (DMAP, 2 mg) in toluene
z
aq. H
3
PO
4
4
1
HX-105 instrument (Jeol , Tokyo, Japan). H-NMR
spectra were measured in CDCl
3
by a Varian Unity
m
INOVA 500 instrument, and IR spectra were
measured by Impact 410 FT-IR apparatus (Nicolet,
U.S.A.). Optical rotation was measured by a
DIP-370 polarimeter (Japan Spectroscopic Co.,
Japan).
?
S
S
R R
W
acetonitrile (1:2, 300
night at 40 C. An aliquot (30
silica gel TLC plate (10 cm length, silica gel 60 F254
m
l). The mixture was kept over-
9
m
l) was loaded onto a
Synthesis of optically pure (S)-3. Sodium hydride
,
(
(
6.0 g, 0.25 mol) was added to 1,12-undecanediol
Art-5744) and developed with n-hexane ethyl acetate
W
50 g, 0.25 mol) in 1000 ml of DMF at 09C, and the
(4:1, v v). The ‰uorescent band where the authentic
W
mixture was stirred for 1 h at 0
9
C and then for 14 h
1-derivatives of 2 and 3 had been developed was col-
at r.t., before 42.3 g (0.25 mol) of benzylbromide
was added to it, to give 12-benzyloxy-1-undecanol
lected and packed in a Pasteur pipette, before eluting
with ethyl acetate methanol (3:1, v v, 1 ml). An
W
W
(
29.2 g, 40.4
1 mmol) and CuBr
solved in 100 ml of CH
stirred for 30 min at 0
28.0 g, 0.11 mol) was then added, and the mixture
was stirred for 1 h to give 12-benzyloxy-1-bromoun-
decane (22.4 g, 88.7 ). This bromide (4.7 g,
9 mmol) was reacted with magnesium (1.6 g,
7 mmol) in THF to give the corresponding Grignard
)-2-Methylbutyl tosylate (1.6 g, 6.2 mmol)
and a catalytic amount of CuI were added to the
reagent at 0 C, before the mixture was stirred at 0
for 1 h and then at r.t. for 14 h to give ( )-1-
benzyloxy-14-methylhexadecane (0.61 g, 28.3 ).
Catalytic debenzylation of this compound over
palladium-carbon in ethanol gave ( )-14-methylhex-
adecan-1-ol (0.54 g, 89.0 ). This alcohol (0.5 g,
.9 mmol) was oxidized with KMnO (0.93 g,
.9 mmol) in 20 ml of a 1:1 mixture of pyridine and
C for 16 h to
z
). This monobenzyloxyalcohol (20.8 g,
(28.3 g, 85 mmol) were dis-
Cl , and the mixture was
C. Triphenylphosphine
aliquot (10
HPLC column (Develosil C-30 UG-5, 5
I.D. 150 mm, Nomura Chemical Co., Japan) and
eluted with methanol at 1.0 ml min and 30
m
l) was injected into a reversed-phase
7
4
m
M
, 4.6 mm
2
2
×
„1
9
9
C. Each
(
peak at 9.8 and 14.0 min, where the authentic 1-
derivatives of 2 and 3 had respectively been eluted,
z
was collected. An aliquot (1
chiral analysis.
ml) was used for the
1
6
reagent. (
S
HPLC separation of each diastereomeric
tive of and 3. The 1-derivatives of the anteiso acids
were separated in an ODS column (Develosil ODS-3,
m, 4.6 mm I.D. 150 mm, Nomura Chemical
1-deriva-
2
9
9C
S
3
m
×
z
Co., Japan). The compounds were detected by
monitoring the ‰uorescence intensity at 462 nm (exci-
tation at 298 nm). To separate the 2-derivatives, a
S
z
mixture of acetonitrile THF n-hexane (100:100:5,
W
W
1
5
4
v v v) was used as a mobile phase with a ‰ow rate of
WW
„
1
0.15 ml min , the column being kept at „50
9
C. To
water while vigorously stirring at 55
give (S)-3 (0.26 g, 52.0 ), mp. 34.5 C; [
2.10, CHCl ); IR(neat)
711; H NMR (500 MHz, CDCl
6.4Hz, 3H), 0.85(t, J 7.1Hz, 3H), 1.04–1.20(m,
9
9
separate the 3-derivatives, a mixture of acetonitrile
W
2
0
z
a
]
D
+4.95
max cm : 3400 (broad),
: 0.84(d,
9
THF n-hexane (150:200:15, v v v) was used as a
WW
W
„
1
„1
(
c
3
n
mobile phase with a ‰ow rate of 0.15 ml min , the
column being kept at „45 C.
1
1
J
2
J
2
3
)
d
9
＝
＝
H), 1.20–1.38(m, 21H), 1.63(m, 2H), 2.35(t,
Results and Discussion
＝
7.6Hz, 2H); MS (HRFAB): calcd. for C17
H
33
2
O ,
„
69.2490 ([M-H] ); found, 269.2491.
Preparation of the authentic anteiso acids
Authentic optically pure ( )-2 was prepared by the
S
7
)
HPLC instruments. The HPLC pump used was a
Jasco PU-980 unit (Japan Spectroscopic Co., Tokyo,
Japan) equipped with a Rheodyne 7125 sample injec-
method previously reported, while authentic (
was prepared from commercially available optically
pure ( )-2-methylbutyl tosylate. The tosylate and 12-
benzyloxyundecanyl magnesium bromide were cou-
pled to give ( )-1-benzyloxy-14-methylhexadecane.
After debenzylation, the alcohol was oxidized with
KMnO to give ( )-3.
Although both ( )-2 and (
S)-3
S
tor with a 20-
m
l sample loop. The ‰uorescence detec-
l ‰ow cell, and
tor was a Jasco FP-920 unit with a 5-
m
S
the integrator was a Chromatocorder 12 (System
Instrument, Tokyo, Japan). Cryocool CC100-II was
used to control the column temperature.
4
S
S
S
)-3 gave signiˆcant [
a
]
D
values, they were too small to determine their abso-
Sample preparation procedure from S365A.
Glycoglycerolipid S365A (7 mg) was hydrolyzed for
lute conˆguration with the small amount of each
sample by measuring the [
a
] values of the acids
D
4
h in 40 ml of ethanol 10
z
aq. NaOH (3:1). After
derived from natural products. Fluorescence conver-
sion, however, allowed us to follow the target com-
W
evaporating the ethanol under reduced pressure, the
Akasaka, Kazuaki
