4364
L.-T. Ng et al. / Bioorg. Med. Chem. 17 (2009) 4360–4366
[M+Na]+; HRESIMS (+) m/z: 281.0792 (calcd for C15H14O4Na =
281.0790).
192 °C. 1H NMR (400 MHz, acetone-d6): d = 3.76 (3H, s, OMe),
4.22 (2H, s, CH2), 6.48 (1H, d, J = 8.8 Hz, H-5), 6.87 (2H, d,
J = 8.8 Hz, H-30, 50), 7.25 (2H, d, J = 8.8 Hz, H-20, 60), 7.55 (1H, d,
J = 8.4 Hz, H-6), 7.80 (1H, s, OH), 8.66 (1H, s, OH), 12.74 (1H, s, C-
2 OH). 13C NMR (100 MHz, acetone-d6): d = 44.9 (CH2), 56.1
(OMe), 109.1 (C-5), 114.4 (C-1), 115.4 (C-30, 50), 124.8 (C-6),
128.7 (C-10), 132.0 (C-20, 60), 133.8 (C-3), 153.4 (C-2), 154.1 (C-4),
160.3 (C-40), 205.1 (C@O). ESIMS (+) m/z: 275 [M+H]+.1,2
4.2.5. 3,4-Dihydroxy-30,40-dimethoxydeoxybenzoin (5)
2.66 g, 92.4% (scale: 9.24 mmol). Rf = 0.51 (EtOAc–n-hexane–
acetone = 2.5:7:0.5). Yellowish needles (MeOH-H2O), mp 256-
257 °C. 1H NMR (400 MHz, acetone-d6): d = 3.76, 3.77 (each 3H, s,
OMe), 4.14 (2H, s, CH2), 6.80 (2H, d, J = 2.0, 8.8 Hz, H-60), 6.85
(1H, d, J = 8.0 Hz, H-50), 6.90 (2H, d, J = 8.0 Hz, H-5), 6.91 (1H, d,
J = 2.0 Hz, H-20), 7.54 (1H, d, J = 2.0 Hz, H-2), 7.56 (1H, dd, J = 2.0,
8.0 Hz, H-6), 8.49 (2H, br, OH). 13C NMR (100 MHz, acetone-d6):
d = 44.3 (CH2), 55.4 (OMe), 55.4 (OMe), 112.2 (C-50), 113.8 (C-20),
115.0 (C-2), 115.5 (C-5), 121.8 (C-60), 122.6 (C-6), 128.5 (C-1),
129.8 (C-10), 132.0 (C-20, 60), 145.2 (C-4), 148.5 (C-40), 149.6 (C-
30), 150.3 (C-3), 195.9 (C@O). ESIMS (+) m/z: 311 (M+Na); HRESMS
(+) m/z: 311.0893 (calcd for C16H16O5Na = 311.0895).
4.2.11. 2,3,4,40-Tetrahydroxydeoxybenzoin (11)
1.42 g, 5.46% (scale: 54.6 mmol). Rf = 0.35 (EtOAc–n-hexane–
acetone = 4:5.5:0.5). Colorless needles (MeOH–H2O), mp 281–
282 °C. 1H NMR (400 MHz, acetone-d6): d = 4.18 (2H, s, CH2), 6.48
(1H, d, J = 8.8 Hz, H-5), 6.78 (2H, d, J = 8.8 Hz, H-30, 50), 7.16 (2H,
d, J = 8.8 Hz, H-20, 60), 7.55 (1H, d, J = 8.8 Hz, H-6), 8.27 (3H, br,
OH), 12.77 (1H, br s, C-2 OH). 13C NMR (100 MHz, acetone-d6):
d = 43.6 (CH2), 107.7 (C-5), 113.0 (C-1), 115.5 (C-30, 50), 123.5 (C-
6), 126.1 (C-10), 130.7 (C-20, 60), 132.5 (C-3), 152.0 (C-2), 152.8
(C-4), 156.5 (C-40), 203.9 (C@O). EIMS m/z: 260 [M]+, 153 [ring
A+C@O]+.1,2,16
4.2.6. 2,5-Dihydroxy-40-methoxy-3,4-dimethyldeoxybenzoin (6)
1.24 g, 43.4% (scale: 4.34 mmol). Rf = 0.60 (EtOAc–n-hexane–
acetone = 2.5:7:0.5). Colorless needles (MeOH), mp 177–178 °C.
1H NMR (400 MHz, CDCl3): d = 2.19 (3H, s, Ar-Me), 2.22 (3H, s,
Ar-Me), 3.78 (3H, s, OMe), 4.11 (2H, s, CH2), 6.86 (2H, d,
J = 8.4 Hz, H-30, 50), 7.07 (1H, s, H-6), 7.14 (2H, d, J = 8.4 Hz, H-20,
60), 12.32 (1H, s, C-2 OH). 13C NMR (100 MHz, CDCl3): d = 11.5
(Ar-Me), 13.0 (Ar-Me), 44.1 (CH2), 55.3 (OMe), 111.6 (C-6), 114.2
(C-30, 50), 115.6 (C-1), 126.2 (C-3), 127.1 (C-10), 130.4 (C-20, 60),
134.5 (C-4), 145.5 (C-5), 155.7 (C-2), 158.6 (C-40), 203.4 (C@O).
EIMS m/z: 286 [M]+, 165 [ring A + C@O]+; HRESIMS (+) m/z:
309.1101 (calcd for C15H14O5Na = 309.1103).
4.2.12. 2,3,4-Trihydroxy-30,40-dimethoxydeoxybenzoin (12)
2.42 g, 79.6% (scale: 7.96 mmol). Rf = 0.43 (EtOAc–n-hexane–
acetone = 4:5.5:0.5). Colorless needles (MeOH–H2O), mp 166–
167 °C. 1H NMR (400 MHz, acetone-d6): d = 3.76 (3H, s, OMe),
3.77 (3H, s, OMe), 4.20 (2H, s, CH2), 6.48 (1H, d, J = 8.8 Hz, H-5),
6.84 (2H, dd, J = 2.0, 8.4 Hz, H-60), 6.87 (2H, d, J = 8.4 Hz, H-50),
6.96 (1H, d, J = 2.0 Hz, H-20), 7.55 (1H, d, J = 8.8 Hz, H-6), 7.96
(1H, br, OH), 8.78 (1H, br, OH), 12.74 (1H, s, C-2 OH). 13C NMR
(100 MHz, acetone-d6): d = 45.3 (CH2), 56.7 (OMe ꢁ 2), 109.1 (C-
5), 113.5 (C-50), 114.4 (C-1), 115.0 (C-20), 123.1 (C-60), 124.7 (C-
6), 129.2 (C-10), 133.9 (C-3), 150.0 (C-2), 151.0 (C-40), 153.4 (C-
41), 154.1 (C-4), 205.0 (C@O). ESIMS (+) m/z: 305 [M+H]+.35
4.2.7. 2,5-Dihydroxy-4-methoxydeoxybenzoin (7)
2.24 g, 86.8% (scale: 8.68 mmol). Rf = 0.45 (EtOAc–n-hexane–
acetone = 2.5:7:0.5). Yellowish powders (MeOH–H2O), mp 154–
155 °C. 1H NMR (400 MHz, CDCl3): d = 3.91 (3H, s, OMe), 4.19
(2H, s, CH2), 6.44 (1H, s, H-3), 7.26–7.34 (total 5H, m, H-20–60),
7.33 (1H, s, H-6), 12.47 (1H, s, C-2 OH). 13C NMR (100 MHz, CDCl3):
d = 45.2 (CH2), 56.4 (OMe), 100.2 (C-3), 112.0 (C-1), 113.8 (C-6),
127.3 (C-40), 129.0 (C-30,50), 129.6 (C-20, 60), 134.5 (C-10), 138.3
(C-5), 154.1 (C-2), 159.8 (C-4), 202.2 (C@O). EIMS m/z: 258 [M]+,
167 [ring A + C@O]+.34
4.2.13. 2,3,40-Trihydroxy-4-methoxydeoxybenzoin (13)
2.15 g, 78.5% (scale: 7.85 mmol). Rf = 0.23 (EtOAc–n-hexane–
acetone = 3:6.5:0.5). Colorless powders (MeOH–H2O), mp 249–
250 °C. 1H NMR (400 MHz, acetone-d6): d = 3.91 (3H, s, OMe),
4.21 (2H, s, CH2), 6.65 (1H, d, J = 8.8 Hz, H-5), 6.79 (2H, d,
J = 8.4 Hz, H-30, 50), 7.16 (2H, d, J = 8.4 Hz, H-20, 60), 7.63 (1H, d,
J = 8.4 Hz, H-6), 8.24 (1H, br, OH), 12.46 (1H, br, C-2 OH). 13C
NMR (100 MHz, acetone-d6): d = 43.9 (CH2), 55.8 (OMe), 103.5 (C-
5), 114.2 (C-1), 115.5 (C-30, 50), 122.9 (C-6), 126.1 (C-10), 130.6
(C-20, 60), 134.5 (C-3), 151.9 (C-2), 153.2 (C-4), 156.5 (C-40), 204.2
(C@O). ESIMS (+) m/z: 297 [M+Na]+; HRESIMS (+) m/z: 297.0741
(calcd for C15H14O5Na = 297.0739).
4.2.8. 2,4,5-Trihydroxy-40-methoxydeoxybenzoin (8)
2.18 g, 79.6% (scale: 7.96 mmol). Rf = 0.24 (EtOAc–n-hexane–
acetone = 3:6.5:0.5). Pinkish needles (MeOH–H2O), mp 188–
189 °C. 1H NMR (400 MHz, acetone-d6): d = 3.77 (3H, s, OMe),
4.15 (2H, s, CH2), 6.36 (1H, s, H-3), 6.88 (2H, d, J = 8.8 Hz, H-30,
50), 7.24 (2H, d, J = 8.8 Hz, H-20, 60), 7.42 (1H, s, H-6), 12.42 (1H, s,
C-2 OH). 13C NMR (100 MHz, acetone-d6): d = 43.8 (CH2), 54.8
(OMe), 103.3 (C-3), 111.4(C-1), 114.1 (C-30, 50), 115.8(C-6), 127.4
(C-10), 130.6 (C-20, 60), 138.1 (C-5), 154.3 (C-4), 158.9 (C-2), 159.8
(C-40), 202.6 (C@O). EIMS m/z 274 [M]+, 153 [ring A + C@O]+.34
4.2.14. 2,4,6-Trihydroxydeoxybenzoin (14)
1.77 g, 72.5% (scale: 7.25 mmol). Rf = 0.26 (EtOAc–n-hexane–
acetone = 2.5:7:0.5). Yellowish granules (MeOH-H2O), mp 164 °C.
1H NMR (400 MHz, acetone-d6): d = 4.42 (2H, s, CH2), 5.95 (2H, s,
H-3, 5), 7.21 (1H, m, J = 8.4 Hz, H-40), 7.28 (4H, m, H-20, 30, 50, 60),
9.28 (1H, br s, phenolic OH), 11.74 (2H, br s, C-2, 6OH). 13C NMR
(100 MHz, acetone-d6): d = 49.5 (CH2), 95.3 (C-3, 5), 104.5 (C-1),
126.5 (C-40), 128.3 (C-30, 50), 130.0 (C-20, 60), 136.4 (C-10),
164.8(C-2, 6), 164.9 (C-4), 203.0 (C@O). EIMS m/z: 244 [M]+, 153
[ring A + C@O]+.34
4.2.9. 2,4,5,40-Tetrahydroxydeoxybenzoin (9)
1.96 g, 75.4% (scale: 7.54 mmol). Rf = 0.26 (EtOAc–n-hexane–
acetone = 4:5.5:0.5). Colorless needles (MeOH–H2O), mp 297–
299 °C. 1H NMR (400 MHz, acetone-d6): d = 4.10 (2H, s, CH2), 6.35
(1H, s, H-3), 6.79 (2H, d, J = 8.8 Hz, H-30, 50), 7.15 (2H, d,
J = 8.8 Hz, H-20, 60), 7.41 (1H, s,, H-6), 8.40 (3H, br, OH), 12.44
(1H, s, C-2 OH). 13C NMR (100 MHz, acetone-d6): d = 43.9 (CH2),
103.3 (C-3), 111.4 (C-1), 115.6 (C-30,50), 115.8 (C-6), 126.2 (C-10),
130.6 (C-20,60), 138.1 (C-5), 154.4 (C-4), 156.5 (C-2), 159.8 (C-40),
202.7 (C@O). EIMS m/z: 260 [M]+, 153 [ring A + C@O]+.34
4.2.15. 2,4,6-Trihydroxy-40-methoxydeoxybenzoin (15)
2.02 g, 73.7% (scale: 7.37 mmol). Rf = 0.38 (EtOAc–n-hexane–
acetone = 3:6.5:0.5). Reddish needles (MeOH–H2O), mp 184–
185 °C. 1H NMR1H NMR (400 MHz, CD3OD): d = 3.73, (3H, s,
OMe), 7.30 (2H, s, CH2), 5.82 (2H, s, H-3, 5), 6.81 (2H, d,
J = 8.8 Hz, H-30, 50), 7.13 (2H, d, J = 8.8 Hz, H-20, 60). 13C NMR
(100 MHz, CD3OD): d = 49.6 (CH2), 55.6 (OMe), 95.8 (C-3, 5),
105.2 (C-1), 114.6 (C-30, 50), 129.3 (C-10), 131.7 (C-20, 60), 159.7
4.2.10. 2,3,4-Trihydroxy-40-methoxydeoxybenzoin (10)
2.40 g, 87.6% (scale: 8.76 mmol). Rf = 0.46 (EtOAc–n-hexane–
acetone = 3:6.5:0.5). Colorless needles (MeOH–H2O), mp 191–