P.C. Bulman Page et al. / Tetrahedron 70 (2014) 7283e7305
7297
(400 MHz, CDCl3) 3.50 (1H, dd, J2,1¼8.0 Hz, J2,3¼6.2 Hz, H-2),
3.79e3.91 (2H, m, H-6a, H-6b), 3.96e4.02 (1H, m, H-5), 4.11e4.10
(1H, m, OCHHCHX]CH2), 4.22 (1H, dd, J4,3¼6.2 Hz, J4,5¼2.2 Hz, H-
4), 4.32 (1H, ddzt, J3,2¼J3,4¼6.2 Hz, H-3), 4.38e4.44 (1H, m,
OCHHCHX]CH2), 4.45 (1H, d, J1,2¼8.0 Hz, H-1), 4.51 and 4.63 (2H,
2d, J¼11.9 Hz, PhCH2), 4.72 and 4.79 (2H, 2d, J¼11.6 Hz, PhCH2), 5.20
(1H, ddd, Jallylic¼1.3 Hz, JA,B¼1.7 Hz, JA,X¼10.4 Hz, CHx]CHAHB), 5.34
(1H, ddd, Jallylic¼1.7 Hz, JA,B¼1.7 Hz, JB,X¼18.9 Hz, CHX]CHAHB),
5.88 (1H, s, PhCH(O)2), 5.88e5.96 (1H, m, OCH2CHX]CH2),
7.26e7.34 (15H, m, 15ꢂCH arom.); dC (100 MHz, CDCl3) 69.3 (C-6),
70.0 (OCH2CHX]CH2), 72.0 (C-5), 73.5 (CH2), 73.6 (CH2), 76.2 (C-4),
78.7 (C-3), 80.2 (C-2), 101.9 (C-1), 104.6 (PhCH(O)2), 117.3
(OCH2CHX]CH2), 126.3, 127.61, 127.64, 128.1, 128.3, 128.4, 129.1,
134.0 (OCH2CHX]CH2), 137.2, 138.1, 138.2; m/z calcd for
[C30H32O6]þ 488.2199; found for [M]þ: 488.2198.
thiosulfite (2ꢂ5 mL) and water (5 mL), dried (Na2SO4), filtered and
concentrated under reduced pressure. The residue was purified
using silica gel column chromatography (eluent: ethyl acetate/light
petroleum 2:3) to give the desired product 26 (587 mg, 64%) as
a colourless solid and a mixture of anomers (
Mp 137.6 ꢀC (decomp.); [ 21 0.8 (c 1.5, CHCl3). Found C 72.36, H
6.21. C27H28O6 requires C 72.30, H 6.29; nmax (film, CHCl3)/cmꢁ1
3386, 3087, 3030, 1954, 1813, 736, 698; dH (400 MHz, CDCl3) eOH
exchange, 3.51 (1H, ddzt, J2,1¼J2,3¼7.1 Hz, H-2 ), 3.65e3.87 (3H, m,
H-6a , H-6b , H-6a ),
), 3.67 (1H, dd, J2,1¼3.8 Hz, J2,3¼7.1 Hz, H-2
3.76 (1H, t, J¼7.6 Hz, H-6b ), 3.86e3.92 (1H, m, H-5 ), 4.09 (1H, dd,
J4,5¼1.8 Hz, J4,3¼5.6 Hz, H-4 ), 4.12 (1H, dd, J4,5¼2.2 Hz, J4,3¼5.6 Hz,
H-4 ), 4.27 (1H, br s, eOH ), 4.39e4.45 (2H, m, H-3 , H-5 ), 4.47
and 4.61 (2H, 2d, J¼12.2 Hz, PhCH2b), 4.48 and 4.60 (2H, 2d,
J¼12.2 Hz, PhCH2a), 4.68 (1H, dd, J3,2¼7.1 Hz, J3,4¼5.6 Hz, H-3 ),
4.70 (1H, d, partially overlapped, H-1 ), 4.76 and 4.81 (2H, 2d,
J¼12.2 Hz, PhCH2a), 4.86 and 4.88 (each 2H, d, J¼11.7 Hz, PhCH2b),
5.29 (1H, d, J1,2¼3.8 Hz, H-1 ), 5.94 (1H, s, PhCH(O)2b), 5.94 (1H, s,
PhCH(O)2a), 7.14e7.43 (30H, m, 15ꢂCH arom., 15ꢂCH arom.); dC
(100 MHz, CDCl3) 66.8 (C-5 ), 69.4 (C-6 ), 69.6 (C-6 ), 72.2 (C-5 ),
72.6 (CH2a), 73.2 (C-2 ), 73.3 (CH2b), 73.4 (CH2a), 73.5 (CH2b), 73.7
(C-4 ), 74.0 (C-4 ), 74.7 (C-3 ), 77.6 (C-2 ), 79.7 (C-3 ), 90.8 (C-1 ),
96.2 (C-1 ), 103.1 (PhCH(O)2a), 103.2 (PhCH(O)2b), 126.1, 126.4,
a/b
2:1 by 1H NMR).
a
]
D
b
b
a
a
b
a
b
b
b
a
a
b
a
a
b
4.30.2. Second eluting epimer 25b.
a
OBn
O
a
b
Ph
O
a
a
b
b
O
O
a
OBn
25b: 79%
a
b
a
b
b
a
b
20
127.78, 127.83, 127.9, 128.1, 128.19, 128.24, 128.38, 128.44, 128.5,
128.6, 129.2, 137.7, 137.9, 138.9; HRFABMS: m/z calcd for
[C27H28O6]þ: 448.1886; found for [M]þ: 448.1881.
Mp 103 ꢀC (decomp.); [
a
]
D
þ25 (c 1.03, CHCl3); nmax (film,
CH2Cl2)/cmꢁ1 3064, 2905, 1963, 1883, 1819, 1648; dH (400 MHz,
CDCl3) 3.57 (1H, ddzt, J3,2¼J3,4¼7.0 Hz, H-3), 3.78e3.92 (3H, m, H-
6a, H-6b, H-5), 4.13e4.23 (2H, m, H-2, OCHHCHX]CH2), 4.99e4.53
(3H, m, H-1, H-4, OCHHCHX]CH2), 4.53 and 4.61 (2H, 2d, J¼11.4 Hz,
PhCH2), 4.84 and 4.92 (2H, 2d, J¼11.6 Hz, PhCH2), 5.27 (1H, dd,
JA,B¼1.6 Hz, JA,X¼11.3 Hz, CHX]CHAHB), 5.30 (1H, dd, JB,A¼1.6 Hz,
JB,X¼16.0 Hz, CHX]CHAHB), 5.91e5.99 (2H, m, CHX]CHAHB,
PhCH(O)2), 7.19e7.45 (15H, m, 15ꢂCH arom.); dC (100 MHz, CDCl3)
69.7 (C-6), 70.1 (OCH2CHX]CH2), 72.6 (C-5), 73.6 (CH2), 73.8 (CH2),
74.0 (C-3), 80.17 (C-4), 80.19 (C-2), 101.8 (C-1), 103.4 (PhCH(O)2),
117.3 (CHX]CH2),126.8,127.6,127.7,127.9, 128.0,128.2,128.3,128.4,
129.7, 134.0 (CHX]CH2), 138.17, 138.20, 138.5; HRFABMS: m/z calcd
for m/z calcd for [C30H32O6]þ 488.2199; found for [M]þ: found
488.2210.
4.32. 1-Amino-2,6-di-O-benzyl-3,4-benzylidene-1-deoxy-D-
galactopyranose 6
OBn
O
Ph
O
NH2
O
OBn
6
Prepared using general procedure
C using 2,6-di-O-benzyl-
3,4-benzylidene- -galactopyranose 26 (3 g, 6.71 mmol). Silica gel
column chromatography (eluent: trriethylamine/ethyl acetate/light
D
4.31. 2,6-Di-O-benzyl–3,4-O-benzylidene-b-D-galactopyr-
anose 26
petroleum 1:59:40) gave the desired product 6 as a colourless solid
(1.89 g, 63%) as a mixture of anomers (a/b
0.6:1 by 1H NMR).
Mp 96.2 ꢀC (decomp.); [ 22 6.5 (c 1.0, CHCl3); nmax (film, CHCl3)/
a]
D
cmꢁ1 3368, 3031, 1955, 1880, 1812, 741, 697; dH (400 MHz, CDCl3)
eNH2a exchanging, 2.02 (2H, br s, NH2b), 3.35 (1H, dd, J2,3¼6.0 Hz,
J2,1¼7.3 Hz, H-2
m, H-6a , H-6b
(1H, dd, J5,4¼2.16 Hz, J5,6a¼6.0 Hz, H-5
overlapped, H-1
), 4.23 (1H, dd partially overlapped, J4,3¼4.5 Hz, H-
), 4.28 (1H, dd, J5,4¼1.8 Hz, J5,6b¼7.4 Hz, H-5 ), 4.38 (1H, dd,
J3,2¼6.0 Hz, J3,4¼4.5 Hz H-3 ), 4.41e4.44 (1H, m, H-4 ), 4.45 (1H, dd
), 4.51 (1H, d, J¼12.2 Hz,
), 4.52 (1H, d, J¼12.1 Hz, PhCHH ), 4.63 (1H, d, J¼12.1 Hz,
), 4.64 (1H, d, J¼11.1 Hz, PhCHH ), 4.69 (4H, m, PhCH2a
), 5.77 (1H, s, PhCH(O)2a),
5.86 (1H, s, PhCH(O)2b), 7.10e7.42 (26H, m, 13ꢂCH arom., 13ꢂCH
arom.), 7.42e7.56 (4H, m, 2ꢂCH arom., 2ꢂCH arom.); dC
(100 MHz, CDCl3) 68.0 (C-5 ), 69.6 (C-6 ), 70.0 (C-6 ), 72.3 (C-5 ),
72.8 (CH2b), 73.56 (CH2a), 73.59 (CH2a), 73.66 (C-3 ), 73.67 (CH2b),
74.4 (C-4 ), 76.0 (C-2 ), 76.2 (C-4 ), 78.3 (C-1 ), 78.7 (C-3 ), 80.1
(C-2 ), 84.8 (C-1 ), 104.3 (PhCH(O)2a), 104.5 (PhCH(O)2b), 127.0,
b
b
), 3.52e3.63 (2H, m, H-6a
), 3.80 (1H, dd, J2,1¼3.8 Hz, J2,3¼6.2 Hz H-2
a
, H-6b
a
), 3.52e3.38 (2H,
), 4.05
), 4.22 (1H, d partially
b
a
b
Allyl 2,6-di-O-benzyl-3,4-O-benzylidene-
b
-D
-galactopyranoside
b
25b (1.0 g, 2.05 mmol, 1 equiv) and 1,4-diazabicyclo[2.2.2]octane
(42.8 mg, 0.40 mmol, 20 mol %) were dissolved in 95:5 ethanol/
water and the reaction mixture was degassed. Wilkinson’s catalyst
(90 mg, 0.098 mmol, 5 mol %) was then added. The solution was
heated for 21 h at 80 ꢀC after which time it was allowed to cool to
room temperature. The solvents were removed under reduced
pressure and the resulting residue dissolved in dichloromethane
(5 mL), dried (Na2SO4), filtered and concentrated under reduced
pressure to afford the crude enol ether. The crude enol ether was
dissolved in tetrahydrofuran (30 mL), water (8 mL) and pyridine
(0.8 mL) and iodine (2.23 g, 12.7 mmol, 6.2 equiv) was added. The
solution was stirred for 10 min at ambient temperature. After this
period, the reaction mixture was cooled to 0 ꢀC and treated with
10% aqueous sodium thiosulfite (5 mL). After 15 min at 0 ꢀC the
solution was extracted with ethyl acetate (3ꢂ35 mL). The combined
aqueous extracts were washed with 10% aqueous sodium
4b
a
b
a
partially overlapped, J,3,4¼4.0 Hz, H-3
a
PhCHH
b
a
b
b
PhCHH
,
PhCH2b), 4.93 (1H, d, J1,2 ¼3.6 Hz, H-1
a
a
a
b
a
b
a
b
a
b
a
a
a
b
a
b
b
b
127.1, 127.68, 127.76, 127.79, 127.87, 127.89, 127.93, 128.0, 128.3,
128.39, 128.41, 128.42, 128.44, 128.47, 128.55, 129.4, 129.7, 136.9,
137.3, 137.4, 138.0, 138.1, 138.2; m/z calcd for [C27H29NO5þH]þ:
448.2124; found for [MþH]þ: 448.2120.