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Helvetica Chimica Acta ± Vol. 82 (1999)
(s, HO C(5)); 8.09 (d, J 6.6, H C(2'), H C(6')); 7.64 ± 7.57 (m, H C(3'), H C(4'), H C(5')); 7.09
(s, H C(3)); 6.85 (d, J 1.5, H C(8)); 6.48 (d, J 1.5, H C(6)); 5.78 (d, J 8.1, H C(1'')); 5.41 (t, J 9.5,
H
C(4'')); 5.12 (dd, J 8.1, 9.5, H C(2'')); 5.03 (t, J 9.5, H C(3'')); 4.35 (m, H C(5'')); 4.20 (dd, J 11.8,
5.9, Hpro-R C(6'')); 4.12 (d, J 11.8, Hpro-S C(6'')); 2.03 (s, 3 Ac); 1.99 (s, Ac). 13C-NMR (CDCl3/(D6)DMSO
9 : 1, 50 MHz): 182.5 (C(4)); 170.6 (CO of Ac); 170.1 (CO of Ac); 169.4 (CO of Ac); 169.2 (CO of Ac); 164.45
(C(2)); 162.3 (C(7)); 162.1 (C(5)); 157.4 (C(9)); 132.1 (C(4')); 131.1 (C(1')); 129.1 (C(3'), C(5')); 126.3 (C(2'),
C(6')); 107.0 (C(3)); 106.0 (C(10)); 99.9 (C(1'')); 98.1 (C(6)); 95.6 (C(8)); 72.6 (C(5'')); 72.4 (C(3'')); 71.0
(C(2'')); 68.3 (C(4'')); 62.0 (C(6'')); 20.6 (Me).
7-(b-d-Glucopyranosyloxy)-5-hydroxy-2-phenyl-4H-1-benzopyran-4-one (1). A soln. of the compound
described above (1.44 g, 2.46 mmol) in 1m KOH/EtOH (40 ml) was refluxed for 3 h under N2. After cooling,
addition of Dowex 50 (H form) to pH 3 (wet pH paper), filtration, and drying under vacuum, 1 (1.025 g, 99%)
was obtained. Yellow powder. UV/VIS (MeOH): 268, 306. TLC (AcOEt/butan-2-one/HCOOH/H2O
30 :2 :1:1): Rf 0.32. 1H-NMR ((D6)DMSO, 300 MHz): 12.81 (s, HO C(5)); 8.11 (d, J 6.6,
H C(2'),
H
C(6')); 7.62 ± 7.59 (m, H C(3'), H C(4'), H C(5')); 7.07 (s, H C(3)); 6.88 (d, J 1.5, H C(8)); 6.48
(d, J 1.5, H C(6)); 5.09 (d, J 6.6, H C(1'')); 3.71 (d, J 10.3, Hpro-S C(6'')); 3.50 ± 3.20 (m, H C(2''),
H
C(3''), H C(4''), H C(5'')); Hpro-R C(6'')). 13C-NMR (CDCl3/(D6)DMSO 9 : 1, 75 MHz): 183.0 (C(4));
164.6 (C(2)); 164.0 (C(7)); 162.0 (C(5)); 158.0 (C(9)); 133.1 (C(4')); 131.4 (C(1')); 130.1 (C(3'), C(5')); 127.4
(C(2'), C(6')); 106.4 (C(3)); 106.3 (C(10)); 100.7 (C(1'')); 100.5 (C(6)); 95.8 (C(8)); 78.0 (C(5'')); 77.3 (C(3''));
73.9 (C(2'')); 70.4 (C(4'')); 61.4 (C(6'')). FAB-MS (pos. mode): 417.1.
5-Hydroxy-2-phenyl-7-(tetra-O-acetyl-b-d-galactopyranosyloxy)-4H-1-benzopyran-4-one. Synthesized ac-
cording to the procedure described above for 5-hydroxy-2-phenyl-7-(tetra-O-acetyl-b-d-glucopyranosyloxy)-4H-
1-benzopyran-4-one with tetra-O-acetyl-a-d-galactopyranosyl bromide as the glycosyl donor. Yield 81%
(orange powder). TLC (AcOEt/petroleum ether 2 :3): Rf 0.54. HPLC (AcOEt/petroleum ether 1 :1): tR 6.2 min.
1H-NMR (CDCl3/300 MHz): 12.73 (s, HO C(5)); 7.89 (d, J 5.9,
H C(2'), H C(6')); 7.58 ± 7.51
(m, H C(3'), H C(4'), H C(5')); 6.70 (s, H C(3)); 6.63 (d, J 2.1, H C(8)); 6.48 (d, J 2.1, H C(6));
5.56 ± 5.49 (m, H C(4''), H C(3'')); 5.16 (d, J 7.4, H C(1'')); 5.14 (H C(2''), partially masked by
H
C(1'')); 4.24 (dd, J 11.0, 5.2, Ha C(6'')); 4.17 ± 4.13 (m, H C(5''), Hb C(6'')); 2.20 (s, Ac); 2.10
(s, 2 Ac); 2.03 (s, Ac). 13C-NMR (CDCl3, 75 MHz): 183.0 (C(4)); 170.9 (CO of Ac); 170.6 (CO of Ac); 170.5
(CO of Ac); 169.7 (CO of Ac); 164.8 (C(2)); 162.8 (C(7)); 162.6 (C(5)); 157.8 (C(9)); 132.5 (C(4')); 131.5
(C(1')); 129.6 (C(3'), C(5')); 126.7 (C(2'), C(6')); 107.4 (C(3)); 106.4 (C(10)); 100.3 (C(1'')); 99.1 (C(6)); 95.9
(C(8)); 71.9 (C(5'')); 71.1 (C(3'')); 68.7 (C(2'')); 67.4 (C(4'')); 61.9 (C(6'')); 21.1 (Me).
7-(b-d-Galactopyranosyloxy)-5-hydroxy-2-phenyl-4H-1-benzopyran-4-one. Synthesized according to the
procedure described for 1. Yield 97% (orange powder). TLC (AcOEt/butanone/HCOOH/H2O 10 :2 :1 :1):
Rf 0.62. 1H-NMR ((D6)DMSO, 300 MHz): 8.09 (d, J 5.9, H C(2'), H C(6')); 7.64 ± 7.57 (m, H C(3'),
H
H
C(4'), H C(5')); 7.06 (s, H C(3)); 6.87 (d, J 2.2, H C(8)); 6.48 (d, J 2.2, H C(6)); 5.04 (d, J 7.4,
C(1'')); 3.70 ± 3.40 (m, H C(2''),
H C(3''), H C(4''), H
C(5''), 2 H C(6'')). 13C-NMR (CDCl3
(D6)DMSO 9 : 1, 75 MHz): 183.0 (C(4)); 164.5 (C(2)); 164.2 (C(7)); 162.0 (C(5)); 158.0 (C(9)); 133.1
(C(4')); 131.5 (C(1')); 130.0 (C(3'), C(5')); 127.4 (C(2'), C(6')); 106.4 (C(3)); 106.3 (C(10)); 101.3 (C(1''));
100.5 (C(6)); 95.8 (C(8)); 76.6 (C(5'')); 74.0 (C(3'')); 70.9 (C(2'')); 68.9 (C(4'')); 61.1 (C(6'')). FAB-MS (pos.
mode): 417.1.
5-Hydroxy-7-[6-O-(p-methoxycinnamyl)-b-d-glucopyranosyloxy]-2-phenyl-4H-1-benzopyran-4-one (2). p-
Methoxycinnamyl chloride (94 mg, 0.48 mmol) was added in several portions to a soln. of 1 (100 mg, 0.24 mmol)
and DMAP (15 mg, 0.12 mmol) in anh. pyridine (20 ml) under N2. After stirring for 96 h at r.t., pyridine was
removed under vacuum. Addition of acetone (20 ml), neutralization by Dowex (H form), filtration, removal of
the solvent under vacuum, and FC (silica gel; AcOEt/petroleum ether 7:3 to pure AcOEt), 2 (43 mg, 31%) was
obtained as a white powder, as well as unreacted 1 (25 mg). UV/VIS (MeOH): 271, 309. TLC (AcOEt): Rf 0.33.
HPLC (AcOEt/petroleum ether 7:3): tR 15.1 min. 1H-NMR ((D6)DMSO, 300 MHz): 12.82 (s, HO C(5)); 8.07
(d, J 7.4, H C(2'), H C(6')); 7.65 ± 7.54 (m, H C(3'), H C(4'), H C(5')); 7.53 (d, J 16.2, H C(b));
7.46 (d, J 8.8, H C(2), H C(6), of acyl); 7.03 (s, H C(3)); 6.87 (d, J 2.2, H C(8)); 6.78 (d, J 8.8,
H
C(3), H C(5) of acyl); 6.49 (d, J 2.2, H C(6)); 6.41 (d, J 16.2, H C(a)); 5.19 (d, J 6.6, H C(1''));
4.85 (d, J 4.4, HO C(2'')); 4.64 ± 4.60 (m, HO C(3''), HO C(4'')); 4.49 (d, J 11.8, Hpro-S C(6'')); 4.16
(dd, J 11.8, 7.4, Hpro-R C(6'')); 3.76 (s, MeO); 3.40 ± 3.70 (m, H C(2''), H C(3''), H C(4''), H C(5'')).
13C-NMR ((D6)DMSO, 75 MHz): 183.0 (C(4)); 167.1 (CO of acyl); 164.4 (C(2)); 163.8 (C(7)); 161.9 (C(5));
157.9 (C(9)); 145.3 (C(b)); 133.0 (C(4')); 131.3 (C(1')); 130.8 (C(4) of acyl); 130.7 (C(2), C(6) of acyl); 129.9
(C(3'), C(5')); 127.2 (C(2'), C(6')); 115.8 (C(a)); 115.2 (C(1) of acyl); 115.0 (C(3), C(5) of acyl); 106.5 (C(3));