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X. Shen et al. / Tetrahedron xxx (2017) 1e8
4.2.12. 3-Hydroxy-5-methoxy-2-(4-hydroxyphenyl)-4H-chromen-
4-one (Fl-14)
7.72 (dd, J ¼ 8.6, 7.1, 1.6 Hz, 1H), 7.61 (d, J ¼ 8.5 Hz, 1H), 7.44 (t,
J ¼ 7.5 Hz, 1H), 7.08 (dd, J ¼ 9.5, 2.5 Hz, 2H), 3.93 (s, 3H). 13C NMR
A yellow needles; yield: 40%; mp: 240e242 ꢀC (CH3OHeH2O);
(100 MHz, CDCl3) d 173.14, 161.11, 155.30, 145.31, 137.64, 133.36,
1H NMR (400 MHz, DMSO)
d
10.08 (s, 1H), 8.95 (s, 1H), 8.07 (d,
129.53, 125.42, 124.43, 123.56, 120.73, 118.18, 114.11, 77.33, 77.01,
76.69, 55.42. HR-ESIMS: 267.0647 [M ꢂ H]- (calc. for C16H11O4,
267.0652).
J ¼ 8.9 Hz, 2H), 7.66 (t, J ¼ 8.4 Hz, 1H), 7.24 (d, J ¼ 8.3 Hz, 1H),
6.99e6.89 (m, 3H), 3.90 (s, 3H), 3.38 (s, 14H). 13C NMR (100 MHz,
DMSO)
d 172.21, 159.49, 159.32, 156.82, 143.38, 138.35, 134.20,
129.57, 122.25, 115.93, 112.10, 110.39, 106.13, 56.65, 40.58, 40.37,
40.17, 39.96, 39.75, 39.54, 39.33. HR-ESIMS: 285.0757; [MþH]þ
(calc. for C16H13O5, 285.0760).
4.2.19. 3-Hydroxy-2-(4-hydroxyphenyl)-4H-chromen-4-one (Fl-
25)
Yellow solid; yield: 81%; mp: 242e244 ꢀC (CH3OHeH2O); 1H
NMR (400 MHz, CDCl3)
(d, J ¼ 8.4 Hz, 1H), 7.38 (t, J ¼ 7.5 Hz, 1H), 6.85 (t, J ¼ 25.6 Hz, 3H),
3.07 (s, 5H). 13C NMR (100 MHz, CDCl3)
172.53, 155.12, 151.37,
146.67, 136.96, 132.85, 129.22, 125.25, 124.18, 120.90, 118.20, 118.03,
111.53, 77.34, 77.03, 76.71, 40.09. HR-ESIMS: 282.1137; [MþH]þ
(calc. for C17H16NO3, 282.1125).
d 8.33e8.12 (m, 3H), 7.71e7.62 (m, 1H), 7.56
4.2.13. 2-(Furan-2-yl)-3-hydroxy-5-methoxy-4H-chromen-4-one
(Fl-16)
d
Yellow solid; yield: 62%; mp: 200e202 ꢀC (CH3OHeH2O); 1H
NMR (400 MHz, CDCl3)
d
7.71 (s, 1H), 7.60 (t, J ¼ 8.4 Hz, 1H), 7.30 (d,
J ¼ 3.5 Hz, 1H), 7.19 (d, J ¼ 8.5 Hz, 2H), 6.82 (d, J ¼ 8.2 Hz, 1H), 6.67
(dd, J ¼ 3.5, 1.7 Hz, 1H), 4.05 (s, 3H). 13C NMR (100 MHz, CDCl3)
d
172.01, 159.62, 156.98, 144.53, 144.26, 136.58, 133.93, 114.91,
4.2.20. 3-Hydroxy-7-methoxy-2-phenyl-4H-chromen-4-one (Fl-
112.60, 110.46, 105.26, 77.36, 77.04, 76.72, 56.51. HR-ESIMS:
26)
281.0415 [MþNa]þ (calc. for C14H10NaO5, 281.0420).
A yellow needles; yield: 61%; mp: 125e127 ꢀC (CH3OHeH2O);
1H NMR (400 MHz, CDCl3)
d
8.28e8.20 (m, 2H), 8.14 (d, J ¼ 8.9 Hz,
1H), 7.49 (ddd, J ¼ 11.2, 9.5, 6.1 Hz, 3H), 7.09e6.93 (m, 3H), 3.94 (s,
3H). 13C NMR (100 MHz, CDCl3)
172.83, 164.30, 157.40, 144.17,
4.2.14. 3-Hydroxy-5-methoxy-2-(thiophen-2-yl)-4H-chromen-4-
one (Fl-17)
d
Yellow solid; yield: 68%; mp: 204e206 ꢀC (CH3OHeH2O); 1H
138.13, 131.22, 129.90, 128.58, 127.49, 126.78, 114.90, 114.60, 99.86,
NMR (400 MHz, CDCl3)
6.7 Hz, 2H), 7.25 (m, 1H), 7.16 (d, J ¼ 8.5 Hz, 1H), 6.81 (d, J ¼ 8.2 Hz,
1H), 4.05 (s, 3H). 13C NMR (100 MHz, CDCl3)
172.11, 159.60, 156.99,
d
7.98 (d, J ¼ 3.8 Hz, 1H), 7.60 (dd, J ¼ 10.2,
77.34, 77.02, 76.70, 55.88. HR-ESIMS: 283.0969; [MþH]þ (calc. for
C17H15O4, 283.0965).
d
140.30, 136.48, 133.87, 132.77, 129.36, 128.85, 128.06, 111.66, 110.29,
105.21, 56.50. HR-ESIMS: 297.0182 [MþNa]þ (calc. for C14H10NaO4S,
297.0192).
4.2.21. 3-Hydroxy-6-bromo-2-phenyl-4H-chromen-4-one (Fl-27)
Brown solid; yield: 71%; mp: 265 ꢀC (CH3OHeH2O); 1H NMR
(400 MHz, CDCl3)
d
8.38 (d, J ¼ 2.4 Hz, 13H), 8.28e8.19 (m, 28H),
7.77 (dd, J ¼ 9.0, 2.4 Hz, 14H), 7.63e7.43 (m, 57H), 7.26 (s, 5H), 7.01
4.2.15. 5-Fluoro-3-hydroxy-2-(4-methoxyphenyl)-4H-chromen-4-
one (Fl-18)
(s, 14H), 1.60 (s, 5H), 1.25 (s, 1H), 0.00 (s, 9H). 13C NMR (100 MHz,
CDCl3)
d 172.29, 154.13, 145.41, 138.62, 136.63, 130.70, 130.50,
Yellow solid; yield: 76%; mp: 198e200 ꢀC (CH3OHeH2O); 1H
128.69, 127.96, 127.81, 122.00, 120.25, 117.89, 77.35, 77.03, 76.72.
NMR (400 MHz, CDCl3)
d
7.95 (dd, J ¼ 15.4, 3.4 Hz, 1H), 7.64 (d,
HR-ESIMS: 338.9622; [MþNa]þ (calc. for C15H9BrNaO3, 338.9627).
J ¼ 8.8 Hz, 2H), 7.58 (dd, J ¼ 15.4, 1.9 Hz, 1H), 7.41 (td, J ¼ 8.3, 6.4 Hz,
1H), 6.97 (d, J ¼ 8.8 Hz, 2H), 6.84 (d, J ¼ 8.5 Hz, 1H), 6.66 (ddd,
J ¼ 12.1, 8.2, 1.0 Hz, 1H), 3.89 (s, 3H). 13C NMR (150 MHz, CDCl3)
4.2.22. 3-Hydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-
4-one (Fl-28)
d
171.33, 161.23, 159.46, 156.14,144.47, 137.87, 133.33, 129.45, 123.04,
Brown solid; yield: 86%; mp: 192e193 ꢀC (CH3OHeH2O); 1H
114.36e113.84, 111.46, 110.72, 77.22, 77.00, 76.79, 55.42. HR-ESIMS:
309.0523; [MþNa]þ (calc. for C16H11FNaO4, 309.0534).
NMR (400 MHz, CDCl3)
1H), 7.16e6.96 (m, 6H), 3.95 (s, 3H), 3.91 (s, 3H). 13C NMR (100 MHz,
CDCl3) 172.58,164.06,160.83,157.16,144.62,137.27,129.21,126.68,
d
8.22 (d, J ¼ 7.6 Hz, 2H), 8.14 (d, J ¼ 8.8 Hz,
d
4.2.16. 3-Hydroxy -2-phenyl-4H-chromen-4-one (Fl-22)
123.69, 114.67, 114.03, 99.84, 55.85, 55.41. HR-ESIMS: 299.0914;
A brown needles; yield: 84%; mp: 168e170 ꢀC (CH3OHeH2O);
[MþH]þ (calc. for C17H15O5, 299.0903).
1H NMR (400 MHz, CDCl3)
d
8.29 (d, J ¼ 7.5 Hz, 3H), 7.78e7.71 (m,
1H), 7.66e7.54 (m, 3H), 7.54e7.41 (m, 2H), 7.06 (s, 1H). 13C NMR
(100 MHz, CDCl3) 173.51, 155.43, 144.94, 138.49, 133.66, 131.08,
4.3. The synthesis of aurones
d
130.21, 128.62, 127.78, 125.48, 124.53, 120.66, 118.30, 77.38, 77.26,
77.06, 76.74. HR-ESIMS: 239.0713; [MþH]þ (calc. for C15H11O3,
239.0703).
The aurones were obtained using the general procedure for the
synthesis of flavonols.
4.3.1. 4-Methoxy-2-(naphthalen-1-ylmethylene) benzofuran-
3(2H)-one (Aurone-1)
4.2.17. 3-Hydroxy -2-(4-clorophenyl)-4H-chromen-4-one (Fl-23)
Yellow solid; yield: 80%; mp: 171e185 ꢀC (CH3OHeH2O); 1H
Yellow solid; yield: 89%; mp: 184e186 ꢀC (CH3OHeH2O); 1H
NMR (400 MHz, CDCl3)
1.7 Hz, 1H), 7.59 (d, J ¼ 8.5 Hz, 1H), 7.56e7.47 (m, 2H), 7.48e7.39 (m,
1H), 7.07 (s, 1H). 13C NMR (100 MHz, CDCl3)
173.43, 155.40, 143.77,
d
8.32e8.16 (m, 3H), 7.72 (ddd, J ¼ 8.7, 7.1,
NMR (400 MHz, CDCl3)
d
8.43 (d, J ¼ 6.8 Hz, 1H), 8.33 (d, J ¼ 8.4 Hz,
1H), 7.90 (dd, J ¼ 7.8, 4.2 Hz, 2H), 7.65 (s,1H), 7.58 (ddd, J ¼ 19.7,11.0,
d
5.8 Hz, 4H), 6.90 (d, J ¼ 8.2 Hz, 1H), 6.65 (d, J ¼ 8.3 Hz, 1H), 4.03 (s,
138.50, 136.23, 133.86, 129.56, 129.03, 128.93, 125.54, 124.69,
120.61, 118.27, 77.34, 77.22, 77.02, 76.70. HR-ESIMS: 271.0156
3H). 13C NMR (100 MHz, CDCl3)
d 182.28, 167.20, 158.69, 147.80,
138.44, 133.74, 132.28, 130.28, 129.96, 128.91, 128.45, 127.00, 126.17,
125.58, 123.56, 111.04, 107.55, 105.26, 104.86, 56.33. HR-ESIMS:
325.0827; [MþNa]þ (calc. for C20H14NaO3, 325.0835).
[M ꢂ H]- (calc. for C15H385ClO3, 271.0157), 273.0122 [M ꢂ H]- (calc.
37
for C
H
ClO3, 273.0127).
15
8
4.2.18. 3-Hydroxy-2-(4-methoxyphenyl)-4H-chromen-4-one (Fl-
4.3.2. 4-Methoxy-2-(2-methoxybenzylidene) benzofuran-3(2H)-
one (Aurone-3)
24)
A colourless needles; yield: 64%; mp: 231e232 ꢀC (CH3O-
White solid; yield: 50%; mp: 199e201 ꢀC (CH3OHeH2O); 1H
HeH2O); 1H NMR (400 MHz, CDCl3)
d
8.27 (dd, J ¼ 9.5, 2.5 Hz, 3H),
NMR (400 MHz, CDCl3)
d
8.30 (d, J ¼ 7.3 Hz, 1H), 7.58 (t, J ¼ 8.2 Hz,
Please cite this article in press as: Shen X, et al., Synthesis of 5-subsituted flavonols via the Algar-Flynn-Oyamada (AFO) reaction: The