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G. Gu et al. / Carbohydrate Research 341 (2006) 2478–2486
d 174.3 (C-60), 73.9 (C-3), 72.8 (C-4), 64.8 (C-2), 54.3
(C-5), 52.3 (OCH3), 39.8 (C-10), 39.1 (C-1), 33.3 (C-50),
27.1 (C-30), 23.6 (C-40), 23.4 (C-20), 13.4 (C-6); MAL-
DI-TOF MS Calcd for C13H25BF4O5S: 380.21 [M];
Found: 381.34 [M+H]+, 293.25 [MꢀBF4ꢀ]+. HRMS
Calcd for C13H25BF4O5S: 293.1417 [MꢀBF4]+; Found:
293.1416.
(1H, t, J = 2.0 Hz, H-4), 4.12 (1H, dd, J = 14.0,
3.0 Hz, H-1b0), 4.08 (1H, ddd, J = 7.5, 7.0, 3.5 Hz, H-
2), 3.85 (1H, dd, J = 7.0, 2.0 Hz, H-3), 3.78 (1H, t,
J = 11.0 Hz, H-4b0), 3.62 (1H, dd, J = 13.5, 3.5 Hz, H-
1a), 3.36 (1H, dd, J = 13.5, 7.5 Hz, H-1b), 1.63 (3H, d,
H-6); 13C NMR (100 MHz, CD2Cl2): d 126.3–138.2
(24C, Ar), 101.9 (PhCH), 79.5 (C-3), 76.4 (C-20), 75.3
(C-4), 74.7, 74.5 (2C, PhCH2), 74.3 (C-2), 72.9 (PhCH2),
69.6 (C-40), 66.8 (C-30), 51.1 (C-5), 43.3 (C-10), 36.5 (C-
1), 14.4 (C-6). Anal. Calcd for C38H42O9S2: C, 64.57; H,
5.99. Found: C, 64.76; H, 6.00.
3.7. General procedure for preparation of the protected
sulfonium sulfates (18), (20), and (22)
A mixture of 12 (1 mmol), the cyclic sulfate (1.2 equiv),
and anhydrous K2CO3 (40 mg) in HFIP (1.5 mL) was
stirred in a sealed tube in an oil-bath (75 ꢁC) for 40 h.
The solvent was removed under reduced pressure, and
the product was purified by column chromatography.
3.7.3. 2,3,4-Tri-O-benzyl-1,5-dideoxy-1,5-{[(2R,3S,4R,
5R)-2,4-O-benzylidene-5,6-O-isopropylidene-2,4,5,6-tet-
rahydroxy-3-(sulfooxy)hexyl]-episulfoniumylidene}-L-fuc-
itol inner salt (22). Column chromatography [EtOAc/
MeOH, 15:1] of the crude product gave 22 (330 mg,
41%) as an amorphous solid. [a]D ꢀ36 (c 0.5, CH2Cl2);
1H NMR (500 MHz, CD2Cl2): d 7.21–7.50 (20H, m,
Ar), 5.71 (1H, s, PhCH), 4.80 (1H, d, J = 11.0 Hz,
PhCH2), 4.75, 4.71 (2H, 2d, J = 11.5 Hz, PhCH2),
4.61, 4.46 (2H, 2d, J = 11.5 Hz, PhCH2), 4.54–4.59
(2H, m, H-20 and PhCH2), 4.23–4.28 (4H, m, H-30, H-
40, H-50, and H-6a0), 4.20 (1H, dd, J = 9.0, 7.0 Hz, H-
6b0), 4.17 (1H, dd, J = 14.5, 6.5 Hz, H-1a0), 4.09–4.14
(2H, m, H-2 and H-4), 3.95 (1H, dq, J = 7.0, 2.0 Hz,
H-5), 3.88 (1H, dd, J = 14.5, 4.5 Hz, H-1b0), 3.84 (1H,
dd, J = 8.0, 2.0 Hz, H-3), 3.78 (1H, dd, J = 13.2,
3.3 Hz, H-1a), 3.62 (1H, dd, J = 13.2, 7.8 Hz, H-1b),
1.49 (3H, d, J = 7.0 Hz, H-6), 1.36, 1.35 (6H, 2s,
(CH3)2C); 13C NMR (100 MHz, CD2Cl2): d 126.5–
138.2 (24C, Ar), 108.5 ((CH3)2C), 101.3 (PhCH), 80.0
(C-3), 79.5 (C-30), 76.0 (C-4), 75.5 (C-40), 75.2 (C-2),
74.9, 74.4 (2C, PhCH2), 73.7 (C-50), 72.8 (PhCH2),
69.8 (C-20), 65.0 (C-60), 51.7 (C-5), 43.9 (C-10), 37.0
(C-1), 26.5, 25.7 (2C, (CH3)2C), 14.4 (C-6). Anal. Calcd
for C43H50O11S2: C, 64.00; H, 6.25. Found: C, 64.08; H,
6.08.
3.7.1. 2,3,4-Tri-O-benzyl-1,5-dideoxy-1,5-{[(2R,3R)-2,4-
O-benzylidene-2,4-dihydroxy-3-(sulfooxy)butyl]-episulfo-
niumylidene}-L-fucitol inner salt (18). Column chroma-
tography [CHCl3/MeOH, 10:1] of the crude product
gave 18 (645 mg, 91%) as an amorphous solid. [a]D
1
ꢀ54 (c 0.5, CH2Cl2); H NMR (500 MHz, CD2Cl2): d
7.08–7.56 (20H, m, Ar), 5.55 (1H, s, PhCH), 4.75, 4.53
(2H, 2d, J = 11.0 Hz, PhCH2), 4.74, 4.71, (2H, 2d,
J = 11.5 Hz, PhCH2), 4.67, 4.52 (2H, 2d, J = 11.5 Hz,
PhCH2), 4.54 (1H, dd, J = 11.0, 4.5 Hz, H-4a0), 4.53
(1H, ddd, J = 7.5, 4.5, 3.5 Hz, H-30), 4.25 (1H, dt,
J = 8.0, 3.5 Hz, H-20), 4.17 (1H, ddd, J = 8.0, 7.0,
3.5 Hz, H-2), 4.16 (1H, dd, J = 14.2, 8.0 Hz, H-1a0),
4.09 (1H, t, J = 2.5 Hz, H-4), 3.97 (1H, dd, J = 14.2,
3.5 Hz, H-1b0), 3.96 (1H, dq, J = 7.0, 2.5 Hz, H-5),
3.90 (1H, dd, J = 13.0, 3.5 Hz, H-1a), 3.88 (1H, dd,
J = 7.0, 2.5 Hz, H-3), 3.79 (1H, dd, J = 11.0, 7.5 Hz,
H-4b0), 3.67 (1H, dd, J = 13.0, 8.0 Hz, H-1b), 1.47
(3H, d, J = 7.0 Hz, H-6); 13C NMR (100 MHz,
CD2Cl2): d 126.2–138.1 (24C, Ar), 101.8 (PhCH), 79.4
(C-3), 76.3 (C-20), 74.6 (C-4), 74.5 (PhCH2), 74.3 (2C,
C-2 and PhCH2), 73.0 (PhCH2), 69.4 (C-40), 66.9 (C-
30), 51.5 (C-5), 44.0 (C-10), 36.2 (C-1), 14.3 (C-6). Anal.
Calcd for C38H42O9S2: C, 64.57; H, 5.99. Found: C,
64.30; H, 5.91.
3.8. General procedure for the deprotection of compounds
(18), (20), and (22) by hydrogenolysis with Pd(OH)2/C
The protected compound (0.4 mmol) was dissolved in
80% HOAc (10 mL) (for 22, the mixture was firstly
stirred at 80 ꢁC for 1 h to remove the isopropylidene
group) and stirred with Pd(OH)2/C (150 mg, 20 wt %)
under H2 (80 psi). After 50 h, the reaction mixture was
filtered through a pad of Celite, and the filtrate was
concentrated. The residue was purified on column
chromatography.
3.7.2. 2,3,4-Tri-O-benzyl-1,5-dideoxy-1,5-{[(2S,3S)-2,4-
O-benzylidene-2,4-dihydroxy-3-(sulfooxy)butyl]-episulfo-
niumylidene}-L-fucitol inner salt (20). Column chroma-
tography [CHCl3/MeOH, 10:1] of the crude product
gave 20 (655 mg, 93%) as an amorphous solid. [a]D
1
ꢀ22 (c 0.5, CH2Cl2); H NMR (500 MHz, CD2Cl2): d
7.12–7.68 (20H, m, Ar), 5.56 (1H, s, PhCH), 4.79, 4.68
(2H, 2d, J = 11.0 Hz, PhCH2), 4.73 (2H, t,
J = 12.2 Hz, PhCH2), 4.54 (1H, dd, J = 11.0, 6.0 Hz,
H-4a0), 4.52 (1H, ddd, J = 11.0, 9.0, 6.0 Hz, H-30),
4.49, 4.43 (2H, 2d, J = 11.5 Hz, PhCH2), 4.39 (1H, dd,
J = 14.0, 4.0 Hz, H-1a0), 4.33 (1H, ddd, J = 9.0, 4.0,
3.0 Hz, H-20), 4.17 (1H, dq, J = 7.0, 2.5 Hz, H-5), 4.14
3.8.1. 1,5-Dideoxy-1,5-{[(2R,3R)-2,4-dihydroxy-3-(sulfo-
oxy)butyl]-episulfoniumylidene}-L-fucitol inner salt (6).
Column chromatography [EtOAc/MeOH/H2O, 7:3:1] of
the residue afforded 6 (123 mg, 88%) as an amorphous
solid. [a]D ꢀ24 (c 1.5, H2O); 1H NMR (500 MHz,