6778 Tachibana et al.
Macromolecules, Vol. 37, No. 18, 2004
under a H2 gas atmosphere. Then, Pd-C was removed by
filtration, and the solution was evaporated. The residue was
purified by gel filtration chromatography (Sephadex G-10,
(d, 1H, J ) 6.4 Hz, AlaNH), 6.94 (d, 1H, J ) 5.6 Hz, ThrNH),
6.39 (d, 1H, J ) 6.4 Hz, NHAc), 5.46 (s, 1H, Ph-CH-O), 5.38
(d, 1H, J ) 5.2 Hz, AlaNH), 5.24-5.09 (m, 5H, H-1, Ph-CH2-
O), 4.71-4.59 (m, 4H, H-2, AlaR, Ph-CH2-O), 4.44 (dd, 1H,
J R,â ) 2.3 Hz, ThrR), 4.28-4.22 (m, 3H, AlaR, Thrâ, H-4), 4.19
(d, J 6a,6b ) 12.3 Hz, H-6a), 3.96-3.92 (m, 2H, H-6b, H-3), 3.69
(s, 1H, H-5), 1.95 (s, 3H, NHAc), 1.42 (d, 3H, J ) 7.1 Hz, Alaâ),
1.39 (d, 3H, J ) 7.0 Hz, Alaâ), 1.13 (d, 3H, J ) 5.7 Hz, Thrγ).
13C NMR (120 MHz, CDCl3) δ: 173.0, 172.2, 170.5, 168.9 (Cd
O), 138.7, 137.7, 136.1, 135.0, 128.9, 128.7, 128.6, 128.6, 128.3,
128.3, 128.2, 128.1, 127.9, 127.5, 126.3 (Ar), 100.9 (Ph-CH-
O), 99.6 (C-1), 74.6, 74.2, 73.4, 70.7, 69.5, 67.6, 67.0, 63.6, 56.2,
49.1, 23.3, 18.3, 18.1, 17.2. HRMS-FAB (m/z): [M + H]+ calcd
for C47H55N4O12, 867.3817; found, 867.3812.
1
water as eluent) to give 14 (41.4 mg, 82%). 14: H NMR (600
MHz, D2O) δ: 5.11 (d, 1 H, J 1,2 ) 3.9 Hz, H-1), 4.86 (dd, 1 H,
J 2,3 ) 10.6 Hz, H-2), 4.44 (d, 1 H, J ) 2.9 Hz, ThrR), 4.25 (q,
1 H, J ) 7.2 Hz, AlaR), 4.22 (m, 1H, Thrâ), 4.13 (q, 1 H, J )
7.1 Hz, AlaR), 4.00-3.98 (m, 2H, H-3, H-5), 3.95 (d, 1 H, J 3,4
) 2.9 Hz, H-4), 3.67 (m, 2H, H-6), 2.07 (s, 3H, OAc), 1.50 (d,
3H, J ) 7.1 Hz, Alaâ), 1.32 (d, 3H, J ) 7.3 Hz, Alaâ), 1.18 (d,
3H, J ) 6.7 Hz, Thrγ). 13C NMR (120 MHz, D2O) δ: 176.5,
173.1, 171.1, 169.7 (CdO), 96.9 (C-1), 75.3, 71.4, 70.8, 69.4,
67.1, 61.2, 57.3, 49.1, 48.8, 20.6 (COCH3), 17.8, 17.0, 16.7.
HRMS-FAB (m/z): [M + H]+ calcd for C47H54N3O13, 868.2037;
found, 466.2060.
N-(Ben zyloxyca r b on yl)-L-a la n yl-O-(2-a cet a m id e-3-O-
b en zyl-2-d eoxy-r-D-ga la ct op yr a n osyl)-L-t h r eon yl-L-a la -
n in e Ben zyl Ester (18). To a solution of 17 (50 mg, 0.058
mmol) in MeOH (2.0 mL) was added CSA (30 mg, 0.13 mmol),
and the mixture was stirred for 3 h. Then, CSA was quenched
with pyridine, and the solution was concentrated. The residue
was purified by flash column chromatography (CHCl3:MeOH
) 100:2, then 100:3) to give 18 (47 mg, quant). 18: [R]20D +28.6
(c 0.75, CHCl3). 1H NMR (600 MHz, CDCl3, δ): 7.36-7.26 (m,
15H, ArH), 7.11 (d, 1H, J ) 6.8 Hz, AlaNH), 7.20 (d, 1H, J )
6.5 Hz, ThrNH), 6.58 (d, 1H, J ) 8.2 Hz, NHAc), 5.46 (d, 1H,
J ) 7.1 Hz, AlaNH), 5.20-5.05 (m, 5H, H-1, Ph-CH2-O ×
4), 4.68 (d, 1H, Ph-CH2-O), 4.57 (m,1H, AlaR), 4.54 (d, 3H,
Ph-CH2-O), 4.48 (dd, 1H, H-2), 4.47 (dd, 1H, J R,â ) 2.3 Hz,
J â,γ ) 7.8 Hz, Thrâ), 4.30-4.23 (br, 2H, AlaR, ThrR), 4.08 (s,
1H, H-4), 3.92 (m, 1H, H-6a), 3.86 (br, 1H, H-5), 3.75 (m, 1H,
H-6b), 3.64 (dd, 1H, J 2,3 ) 10.8 Hz, J 3,4 ) 2.8 Hz, H-3), 2.93 (s,
1H, 4-OH), 2.73 (s, 1H, 6-OH), 1.95 (s, 3H, NHAc), 1.41 (d,
3H, J ) 7.1 Hz, Alaâ), 1.37 (d, 3H, J ) 7.0 Hz, Alaâ), 1.17 (d,
3H, Thrγ). 13C NMR (120 MHz, CDCl3) δ: 173.3, 172.9, 171.1,
169.6 (CdO), 138.3, 136.4, 135.4, 129.1, 129.1, 129.0, 128.9,
128.7, 128.6, 128.3, 127.9 (Ar), 99.1 (C-1), 76.8, 75.1, 71.8, 70.9,
68.1, 67.5, 67.5, 63.4, 56.5, 50.9, 49.0, 48.8, 23.6, 18.6, 18.3,
P oly[L-a la n yl-O-(2-O-a cet yl-r-D-ga la ct op yr a n osyl)-L-
th r eon yl-L-a la n in e] (3). To a stirred solution of 14 (5.0 mg,
0.011 mmol) in DMF (100 µL) was added DMT-MM (3.6 mg,
0.013 mmol) at 0 °C, and the mixture was stirred at the same
temperature overnight. Then, the product in DMF was pre-
cipitated by addition of ethanol and diethyl ether and centri-
fuged. The crude product was separated by gel filtration
chromatography (Sephadex G-25, water as eluent) to give 3
(3.2 mg, 64%). The number-average molecular weight (Mn) and
weight-average molecular weight (Mw) were estimated as 4.0
× 103 and 7.7 × 103, respectively, by GPC analysis as described
in the general procedure. In MALDI-TOF MS analysis using
DHB, precursor ion peaks (m/z) at 911.35 (n ) 2), 1360.75 (n
) 3), 1808.82 (n ) 4), 2256.52 (n ) 5), and 2707.947 (n ) 6)
1
were observed.32 3: H NMR (600 MHz, D2O) δ: 4.97 (d, 1 H,
J 1,2 ) 3.2 Hz, H-1), 4.82 (dd, 1 H, J 2,3 ) 10.4 Hz, H-2), 4.34 (d,
1 H, ThrR), 4.31 (q, 1 H, J ) 7.3 Hz, AlaR), 4.27 (q, 1 H, J )
7.1 Hz, AlaR), 4.17 (dd, 1H, Thrâ), 3.96-3.93 (m, 2H, H-3, H-5),
3.91 (s, 1 H, H-4), 3.62 (m, 2H, H-6), 2.04 (s, 3H, OAc), 1.31
(d, 3H, J ) 7.1 Hz, Alaâ), 1.27 (d, 3H, J ) 6.9 Hz, Alaâ), 1.18
(d, 3H, J ) 7.5 Hz, Thrγ).
N-(Ben zyloxyca r bon yl)-L-a la n yl-O-(2-a zid e-3-O-ben zyl-
4,6-O-ben zylid en e-2-d eoxy-r-D-ga la ctop yr a n osyl)-L-th r e-
on yl-L-a la n in e Ben zyl Ester (16). A mixture of SnCl2 (197
mg, 1.04 mmol), AgClO4 (215 mg, 1.04 mmol), 8 (630 mg, 1.30
mmol), and freshly activated powdered molecular sieves 4 Å
(1.0 g) in dry CH2Cl2 (8 mL) was stirred at room temperature
for 3 h under a nitrogen atmosphere and then cooled to -20
°C. A solution of 1527 (200 mg, 0.52 mmol) in dry CH2Cl2 (2
mL) was added, and the mixture was stirred at -20 °C to room
temperature for 4 days, then diluted with CHCl3, and filtered
thorough Celite. The filtrate was washed with saturated
NaHCO3 and brine, dried (MgSO4), and concentrated. The
crude residue was purified by flash column chromatography
(Hex:EtOAc ) 1:1) to give 16 (230 mg, 53%). â-Isomer of 16
17.8. HRMS-FAB (m/z): [M + H]+ calcd for C40H51N4O12
,
779.3504; found, 779.3505.
N-(Ben zyloxyca r b on yl)-L-a la n yl-O-(2-a cet a m id e-3-O-
ben zyl-2-d eoxy-6-O-su lfo-r-D-ga la ctop yr a n osyl)-L-th r eo-
n yl-L-a la n in e Ben zyl Ester , Sod iu m Sa lt (19). To a solution
of 18 (25 mg, 0.032 mmol) in DMF (2.0 mL) was added Me3N‚
SO3 (9.0 mg, 0.064 mmol), and the mixture was stirred at 40
°C for 44 h. Then, the residue was purified by flash column
chromatography (CHCl3:MeOH ) 95:5, 9:1 then 85:15) and
Dowex 50W-X8 [Na+] to give 19 as its sodium salt (64 mg,
64%). 19: [R]20 +15.4 (c 1.0, CHCl3). 1H NMR (600 MHz,
D
acetone) δ: 7.94 (d, 1H, J ) 6.5 Hz, AlaNH), 7.69 (d, 1H, J )
8.3 Hz, ThrNH), 7.38-7.18 (m, 16H, Ar H, AlaNH), 6.90 (d,
1H, J ) 6.8 Hz, NHAc), 5.17-5.03 (m, 4H, Ph-CH2-O), 4.99
(d, 1H, J 1,2 ) 3.2 Hz, H-1), 4.75 (d, 1H, Ph-CH2-O), 4.61 (dd,
1H, ThrR), 4.51-4.34 (m, 3H, AlaR × 2, Ph-CH2-O), 4.36-
4.33 (br, 2H, H-2, Thrâ), 4.26 (dd, 1H, H-4), 4.25 (dd, 1H, H-5),
4.14 (m, 2H, H-6a, 6b), 3.80 (dd, 1H, J 2,3 ) 10.5 Hz, H-3), 1.95
(s, 3H, NHAc), 1.38 (d, 3H, J ) 7.3 Hz, Alaâ), 1.38 (d, 3H, J )
7.1 Hz, Alaâ), 1.26 (d, 3H, J ) 6.1 Hz, Thrγ). 13C NMR (120
MHz, acetone) δ: 172.5, 170.3 (CdO), 139.4, 137.1, 136.1,
128.4, 128.3, 128.2, 128.1, 128.0, 127.8, 127.7, 127.6, 127.5,
127.4, 127.1, 127.0 (Ar), 97.9 (C-1), 77.2, 76.1, 70.4, 69.8 (C-
6), 66.7, 65.9, 65.5, 56.2, 50.4, 48.0, 21.8, 18.0, 17.1, 16.8.
HRMS-FAB (m/z): [M + H]+ calcd for C40H50N4NaO15S,
881.2891; found, 881.2903.
was not isolated. 16: [R]20 +60.1 (c 1.0, dioxane). 1H NMR
D
(600 MHz, CDCl3) δ: 7.70 (d, 1H, J ) 7.4 Hz, AlaNH), 7.54-
7.28 (m, 20H, ArH), 6.91 (d, 1H, J ) 5.4 Hz, ThrNH), 5.45 (s,
1H, Ph-CH-O), 5.31-5.30 (m, 2H, J 1,2 ) 3.4 Hz, H-1, AlaNH),
5.19-5.05 (m, 4H, Ph-CH2-O), 4.71 (s, 2H, Ph-CH2-O), 4.63
(m, 1H, AlaR), 4.50 (br, 1H, ThrR), 4.27-4.20 (br, 2H, J 6a,6b
)
12.4 Hz, H-6a, AlaR), 4.16 (d, 1H, J 3,4 ) 3.0 Hz, H-4), 4.12
(dd, 1H, J 2,3 ) 10.5 Hz, H-2), 4.03 (dd, 1H, H-3), 3.96 (d, 1H,
H-6b), 3.62 (s, 1H, H-5), 1.42 (d, 3H, J ) 7.2 Hz, Alaâ), 1.39
(d, 3H, J ) 7.0 Hz, Alaâ), 1.07 (d, 3H, J ) 5.5 Hz, Thrγ). 13C
NMR (120 MHz, CDCl3) δ: 172.8, 172.2, 168.1 (CdO), 138.4,
138.0, 136.5, 135.8, 129.5, 129.0, 129.0, 128.8, 128.6, 128.6,
128.5, 128.3, 128.1, 126.7 (Ar), 101.5 (Ph-CH-O), 97.9 (C-1),
76.3, 73.6, 73.2, 71.6, 69.7, 67.4, 63.7, 60.0, 55.3, 51.0, 48.6,
19.3, 18.4, 16.2. HRMS-FAB (m/z): [M + H]+ calcd for
L-Ala n yl-O-(2-a ceta m id e-2-d eoxy-6-O-su lfo-r-D-ga la cto-
p yr a n osyl)-L-th r eon yl-L-a la n in e, Sod iu m Sa lt (20). To a
solution of 19 (45 mg, 0.051 mmol) in DMF (3 mL), acetic acid
(50 µL), and H2O (0.5 mL) was added 10% Pd(OH)2-C (100
mg), and the mixture was stirred at room temperature
overnight under a H2 gas atmosphere. Then, Pd(OH)2-C was
removed by filtration, and the solution was evaporated. The
residue was purified by gel filtration chromatography (Sepha-
dex G-10, water as eluent), reverse-phase HPLC (Inertsil ODS-
3, GL Science Inc.; gradient 0 f 20% CH3CN in H2O for 60
min), and then Dowex 50W-X8 [Na+] to give 20 as its sodium
salt (16.1 mg, 56%). 20: H NMR (600 MHz, D2O) δ: 4.92 (d,
C
45H52N6O11, 851.3616; found, 851.3619.
N-(Ben zyloxyca r b on yl)-L-a la n yl-O-(2-a cet a m id e-3-O-
ben zyl-4,6-O-ben zylid en e-2-d eoxy-r-D-ga la ctop yr a n osyl)-
L-th r eon yl-L-a la n in e Ben zyl Ester (17). A solution of 16
(120 mg, 0.14 mmol) in AcSH (1 mL) and pyridine (0.5 mL)
was stirred at room temperature for 20 h, and the residue was
purified by flash column chromatography (run 1; hexane:
EtOAc ) 5:1, then acetone, run 2; CHCl3:MeOH ) 99:1 then
97:3) to give 17 (85 mg, 70%). 17: [R]20D +89.2 (c 0.37, CHCl3).
1H NMR (600 MHz, CDCl3) δ: 7.53-7.26 (m, 20H, ArH), 7.10