A. Saito et al. / Tetrahedron 65 (2009) 7422–7428
7427
116.03, 115.97, 115.86 (ꢂ2), 115.78 (ꢂ2), 115.1, 115.0 (ꢂ2), 114.9,
107.6, 107.5, 107.4, 107.2, 102.5, 102.4, 102.3, 101.8, 100.0, 97.3 (ꢂ2),
97.2, 97.0, 96.2, 96.0, 79.5, 76.9, 76.80, 76.76, 76.6, 73.5, 73.1, 72.9
(ꢂ2), 66.7, 37.5 (ꢂ2), 37.3, 37.1, 30.0; FABMS (m/z) 1446 (25), 1465
([MþNa]þ, 33), 1464 (21), 1444 (9.6), 1443 ([MþH]þ, 34), 1442 (20),
1177 (28), 1162 (31), 1100 (37), 1024 (29), 981 (33), 944 (31), 886
(32), 746 (50), 694 (69), 693 (100); FAB-HRMS calcd for C75H63O30
[MþH]þ, 1443.3404; found: 1443.3331.
preparative silica gel column chromatography (hexane/AcOEt/
CHCl3, 9:1 to 2:1) afforded a 57 mg of 18 (0.018 mmol, 57%) as
24
a colorless amorphous: [
a]
ꢀ5.0 (c 0.34, CHCl3), [
a]
24 0.0 (c 0.32,
D
D
EtOAc); 1H NMR (400 MHz, CDCl3, 0.80:0.20 mixture of rotational
isomers) major isomer: 7.48–6.09 (96H, m), 6.32 (0.8H, s), 6.04
(0.8H, d, J¼2.2 Hz), 6.01 (0.8H, br s), 5.94 (0.8H, s), 5.84 (0.8H, br
s), 5.66 (0.8H, d, J¼2.2 Hz), 5.59 (0.8H, br s), 5.58–5.53 (0.8H, m),
5.38–3.96 (34.4H, m), 5.16 (0.8H, br s), 3.92 (0.8H, d, J¼11.7 Hz),
3.81 (0.8H, d, J¼11.7 Hz), 3.27–3.14 (1.6H, m); minor isomer: 7.48–
6.09 (24.6H, m), 6.25 (0.2H, s), 6.04–3.83 (10H, m), 3.27–3.14
(0.4H, m); 13C NMR (100 MHz, CDCl3, 0.80:0.20 mixture of rota-
tional isomers) major isomer: 165.3, 164.2, 163.8, 158.1, 156.6,
156.5, 156.2, 156.1, 155.9, 155.5, 154.7, 153.5, 152.6, 152.1, 152.0,
149.3, 149.1, 148.9, 148.7, 148.1, 148.0, 143.2, 142.23, 142.17, 138.0–
136.4 (Cꢂ24), 131.6, 131.2, 130.6, 128.6–125.9 (Cꢂ50), 125.3, 124.9,
120.2 (ꢂ2), 119.3, 113.9, 113.8, 113.5, 113.4, 113.0, 111.4, 109.84,
109.76, 109.0, 108.8, 106.2, 105.0, 101.7, 93.8, 93.4, 91.9, 90.6, 77.6,
77.5, 76.1, 75.6, 75.0, 74.9, 74.8, 74.7, 72.9, 71.8–68.9 (Cꢂ15), 35.1,
33.8, 26.5; minor isomer was not identified. IR (neat, cmꢀ1) 3090
(w), 3065 (m), 3031 (m), 2936 (m), 2870 (m), 1952 (w), 1860 (w),
1811 (w), 1721 (s), 1593 (s), 1514 (s), 1429 (s), 1373 (s), 1329 (s),
1267 (s), 1217 (s), 1169 (s), 1028 (s), 911 (w), 856 (w); FABMS (m/z)
3236 ([MþNa]þ, 23), 3229 (46), 3218 (56), 3214 ([MþH]þ, 38),
3196 (39), 3042 (51), 3008 (71), 2958 (77), 2900 (100), 2684 (80),
2598 (64), 2586 (62), 2585 (87), 2425 (77), 2411 (76), 2330 (95),
2293 (83), 2244 (88), 2148 (75), 2108 (73), 2061 (94), 1749 (95),
1611 (100).
4.1.7. Peracetate of 3 (14)
Acetylation of 3 (5.9 mg, 5.0
gave 14 (9.5 mg, 4.8
þ68.1 (c 0.45, CHCl3), [
mmol) with general procedure
25
m
a
mol, 95%) as colorless amorphous. [a]
D
24
]
þ79.9 (c 0.48, EtOAc) {lit.3a
[
a
]
þ82.2
D
D
(c 18.7 g Lꢀ1, EtOAc)}; 1H NMR (400 MHz, CDCl3, 0.5:0.5 mixture
of rotational isomers) 7.36–6.69 (12H, m), 6.89 (0.5H, s, 6), 6.77
(0.5H, d, J¼2.2 Hz, A8), 6.75 (0.5H, s, 6), 6.71 (0.5H, s, 6), 6.65
(0.5H, d, J¼2.2 Hz, A6), 6.64 (0.5H, s, 6), 6.62 (0.5H, s, 6), 6.58
(0.5H, s, 6), 6.25 (0.5H, d, J¼2.2 Hz, A8), 5.88 (0.5H, d, J¼2.2 Hz,
A6), 5.74 (0.5H, br s), 5.50–5.46 (1H, m, L3ꢂ2), 5.45 (1H, br s),
5.36 (1H, br s), 5.34 (0.5H, br s), 5.31 (0.5H, br s), 5.29 (1H, br s),
5.22–5.18 (1H, br s, L2ꢂ2), 5.15 (0.5H, br s), 4.97–4.94 (0.5H, m),
4.84 (0.5H, br s), 4.80 (0.5H, br s), 4.76 (0.5H, br s), 4.66 (0.5H, br
s), 4.61 (0.5H, br s), 4.56 (0.5H, br s), 4.51 (0.5H, d, J¼2.2 Hz),
3.10–3.05 (1H, m, L4), 2.99–2.93 (1H, m, L4), 2.38 (1.5H, s, Ac),
2.32 (1.5H, s, Ac), 2.30 (1.5H, s, Ac), 2.290 (1.5H, s, Ac), 2.286
(1.5H, s, Ac), 2.281 (1.5H, s, Ac), 2.27 (6H, s, Ac), 2.26 (3H, s, Ac),
2.25 (1.5H, s, Ac), 2.245 (1.5H, s, Ac), 2.239 (1.5H, s, Ac), 2.22
(4.5H, s, Ac), 2.18 (1.5H, s, Ac), 2.17 (1.5H, s, Ac), 2.05 (1.5H, s, Ac),
1.99 (3H, s, Ac), 1.97 (1.5H, s, Ac), 1.94 (1.5H, s, Ac), 1.91 (1.5H, s,
Ac), 1.89 (1.5H, s, Ac), 1.88 (3H, s, Ac), 1.86 (1.5H, s, Ac), 1.85 (1.5H,
s, Ac), 1.79 (1.5H, s, Ac), 1.77 (1.5H, s, Ac), 1.64 (1.5H, s, Ac), 1.52
(1.5H, s, Ac), 1.45 (1.5H, s, Ac), 1.44 (1.5H, s, Ac), 1.43 (1.5H, s, Ac),
1.35 (1.5H, s, Ac), 1.25 (1.5H, s, Ac); 13C NMR (100 MHz, CDCl3)
170.1 (ꢂ2), 170.0 (ꢂ2), 169.2, 169.1, 169.0, 168.9 (ꢂ2), 168.8, 168.7
(ꢂ3), 168.5, 168.39, 168.36, 168.32, 168.29, 168.18, 168.11, 168.1–
167.7 (Cꢂ19), 167.6, 155.9, 154.9, 154.1, 151.91, 151.88, 151.84, 151.7,
151.6, 149.92, 149.88, 149.85, 149.0, 148.7, 148.6, 148.53, 148.48,
148.0, 147.9, 147.5 (ꢂ2), 147.4, 147.3 (ꢂ2), 147.2, 142.24, 142.18,
142.16, 142.09, 142.07 (ꢂ3), 142.0, 141.94, 141.89, 141.84, 141.81
(ꢂ3), 141.73, 141.69, 136.5, 135.8 (ꢂ2), 135.5, 135.38, 135.35, 135.1,
133.1, 124.9–121.4 (Cꢂ26), 118.5, 118.2, 117.8 (ꢂ2), 117.41, 117.39,
112.7, 112.6, 112.3, 111.7, 111.3, 110.8 (ꢂ2), 110.7, 110.6, 109.9, 109.8,
109.4, 108.2, 107.6, 107.3, 77.6, 77.2–76.6 (Cꢂ3), 76.4, 75.4, 75.1
(ꢂ2), 74.7, 73.9, 71.5, 71.3, 71.0, 70.7, 66.6 (ꢂ2), 35.7, 35.3, 35.2
(ꢂ2), 34.3, 32.9, 26.4 (ꢂ2), 21.1, 21.0, 20.78, 20.76, 20.7–20.6
(Cꢂ18), 20.54, 20.46, 20.44, 20.32, 20.31 (ꢂ2), 20.20, 20.17, 20.12,
4.1.9. [4,8:400,800]-2,3-cis-3,4-trans:200,300-cis-300,400-trans:2&,3&-
trans-Dodeca-O-benzyl-(ꢀ)-epicatechin-(ꢀ)-epicatechin-
(þ)-catechin-3,300,3&-O-(tri-O-benzyl)gallate (20)
To a solution of 17 (155 mg, 0.072 mmol) and 15 (20.9 mg,
0.018 mmol) in CH2Cl2 (40 mL) was added dropwise TMSOTf
(0.036 mL, 0.018 mmol, 0.5 M solution in CH2Cl2) at ꢀ10 ꢁC. After
stirring for 5 min, the pale yellow reaction mixture was quenched
with satd sodium hydrogen carbonate. The aq solution was
extracted with CHCl3 and the organic phase was washed with
water and brine, and dried (Na2SO4). Filtration, concentration, and
preparative silica gel column chromatography (hex–AcOEt–CHCl3,
9:1–2:1) afforded a 44 mg of 19 (0.014 mmol, 76%) as a colorless
26
25
amorphous: [
a
]
þ50.9 (c 0.60, CHCl3), [
a]
þ46.5 (c 0.62,
D
D
EtOAc); 1H NMR (400 MHz, CDCl3, 0.70:0.30 mixture of rotational
isomers) major isomer: 7.48–6.25 (84H, m), 6.41 (0.7H, s), 6.01
(0.7H, d, J¼2.2 Hz), 5.95 (0.7H, s), 5.92 (0.7H, br s), 5.75 (0.7H, br
s), 5.66 (0.7H, d, J¼2.2 Hz), 5.51 (0.7H, br s), 5.26–5.20 (0.7H, m),
5.20 (0.7H, br s), 5.14–5.13 (0.7H, m), 5.13 (0.7H, br s), 5.10–4.46
(25.2H, m), 4.44 (0.7H, d, J¼13.9 Hz), 4.36 (0.7H, d, J¼12.2 Hz),
4.29 (0.7H, d, J¼13.9 Hz), 4.01 (0.7H, d, J¼11.5 Hz), 3.94 (0.7H, d,
J¼11.5 Hz), 3.81 (0.7H, d, J¼11.5 Hz), 3.11 (0.7H, dd, J¼5.6, 16.9 Hz),
2.87 (0.7H, dd, J¼7.5, 17.3 Hz); minor isomer: 7.48–5.58 (36.6H,
m), 6.23 (0.3H, s), 6.07 (0.3H, s), 5.26–3.80 (15H, m), 3.14–3.09
(0.3H, m), 2.97–2.90 (0.3H, m); 13C NMR (100 MHz, CDCl3,
0.70:0.30 mixture of rotational isomers) major isomer: 165.3,
164.7, 163.8, 158.1, 156.6, 156.2, 156.09, 156.07, 155.7, 155.5, 154.9,
152.6, 152.5, 152.1, 149.3, 149.1, 148.8 (ꢂ2), 148.4, 148.2, 143.0,
142.4, 142.1, 138.2–136.4 (Cꢂ24), 131.7, 131.4, 131.0, 128.7–126.8
(Cꢂ54), 120.4, 120.1, 119.6, 113.9, 113.7, 113.6, 113.4, 113.0, 111.0,
109.7, 108.9, 108.8, 106.4, 105.1, 101.7, 93.8, 93.6, 92.0, 90.6, 78.3
(2), 76.0 (2), 75.5 (2), 75.1, 74.9 (ꢂ2), 74.0, 723.9, 71.7–69.1 (Cꢂ16),
34.4 (4), 33.8 (4), 24.9 (4); minor isomer was not identified. IR
(neat, cmꢀ1) 3065 (m), 3032 (m), 2934 (m), 2870 (m), 1952 (w),
1871 (w), 1811 (w), 1720 (s), 1598 (s), 1498 (s), 1429 (s), 1329 (s),
1215 (s), 1119 (s), 1028 (s), 910 (w), 858 (w), 810 (w), 754 (s);
FABMS (m/z) 3236 ([MþNa]þ, 48), 3214 ([MþH]þ, 19), 3149 (37),
3117 (46), 3073 (55), 3019 (44), 2788 (77), 2713 (79), 2666 (87),
2340 (100), 2244 (75), 1987 (85), 1763 (69), 1725 (78).
20.11, 29.05 (ꢂ2), 19.99, 19.7, 19.6, 19.5 (ꢂ2), 19.3; IR (neat, cmꢀ1
)
3063 (m), 2988 (m), 2936 (m), 2853 (w), 2413 (w), 2309 (w),
2091 (w), 1748 (s), 1600 (s), 1507 (s), 1429 (s), 1372 (s), 1262 (s),
1206 (s), 1109 (s), 1043 (s), 976 (m), 949 (m), 902 (s), 841 (m);
FABMS (m/z) 2021 (28), 2020 (59), 2018 (100), 2017 ([MþNa]þ,
100), 1977 (24), 1975 (47), 1894 (29), 1893 (39), 1892 (36), 1791
(28), 1790 (30), 1789 (28), 1382 (26), 1172 (29), 972 (30), 971 (32);
FAB-HRMS calcd for C100H90O44Na [MþNa]þ, 2017.4703; found:
2017.4696.
4.1.8. [4,8:400,800]-2,3-cis-3,4-trans:200,300-cis-300,400-trans:2&,3&-
cis-Dodeca-O-benzyl-tri-(ꢀ)-epicatechin-3,300,3&-O-(tri-O-
benzyl)gallate (18)
To a solution of 16 (284 mg, 0.13 mmol) and 15 (35.0 mg,
0.030 mmol) in CH2Cl2 (60 mL) was added dropwise TMSOTf
(0.036 mL, 0.018 mmol, 0.5 M solution in CH2Cl2) at ꢀ20 ꢁC. After
stirring for 5 min, the pale yellow reaction mixture was quenched
with satd sodium hydrogen carbonate. The aq solution was
extracted with CHCl3 and the organic phase was washed with
water and brine, and dried (Na2SO4). Filtration, concentration, and