RSC Advances
Paper
0
0
0
H-2 ), 5.17 (t, 1H, J ¼ 9.9 Hz, H-4 ), 3.93–3.95 (m, 1H, H-5 ), 2.70– eq). Aer 3 h, the solution was concentrated. Then the residue
2
.77 (m, 2H, COCH ), 2.49–2.55 (m, 2H, COCH ), 2.19, 2.16, 2.09 was puried by silica gel column chromatography (petroleum
2
2
1
3
(
s, each 3H, 3 ꢃ CH CO), 1.22 (t, 3H, J ¼ 6.0 Hz, CH ); C NMR ether–acetone) to afford compounds 1–4, respectively.
3
3
0
0
(
CDCl ): d 206.1, 181.1, 171.9, 170.3, 170.1, 163.7, 162.5, 157.6,
1-Hydroxy-3-(2 ,3 -di-O-acetyl-a-L-rhamnopyranosyl)-9H-xanthen-9-
3
1
7
56.1, 135.3, 126.0, 124.3, 120.6, 117.8, 105.1, 99.1, 95.6, 95.0, one (1). White solid in 85.1% yield; R 0.25 (3 : 1, petroleum
f
ꢀ
25
1
6.9, 69.5, 67.9, 37.8, 29.8, 28.0, 20.9, 20.8, 17.5; HRESIMS calcd ether–acetone); m.p. 193–194 C; [a]
12Na 579.1478; found 579.1485. NMR (CDCl
): d 8.25 (dd, 1H, J ¼ 7.7 Hz, 1.7 Hz, Ar-H), 7.73 (td,
-Hydroxy-3-(2 ,3 -di-O-acetyl-4 -levulinyl-a-L-rhamnopyranosyl)- 1H, J ¼ 7.7 Hz, 1.6 Hz, Ar-H), 7.44 (d, 1H, J ¼ 8.8 Hz, Ar-H), 7.38
-methyl-9H-xanthen-9-one (36). White solid in 85.6% yield; (td, 1H, J ¼ 7.7 Hz, 1.1 Hz, Ar-H), 6.64 (d, 1H, J ¼ 2.2 Hz, Ar-H),
D
3
ꢁ87.8 (c 0.10, CHCl ); H
for C28
H
28
O
3
0
0
0
1
6
ꢀ
0
Rf 0.28 (2 : 1, petroleum ether–EtOAc); m.p. 169–170 C; 6.54 (d, 1H, J ¼ 2.2 Hz, Ar-H), 5.55 (d, 1H, J ¼ 1.7 Hz, H-1 ), 5.43
2
5
1
0
[
a] ꢁ102.6 (c 0.10, CHCl ); H NMR (CDCl ): d 12.90 (s, 1H, (dd, 1H, J ¼ 3.3 Hz, 1.7 Hz, H-2 ), 5.33 (dd, 1H, J ¼ 9.9 Hz, 3.3 Hz,
D
3
3
0
0
0
OH), 8.12 (d, 1H, J ¼ 8.2 Hz, Ar-H), 7.24 (s, 1H, Ar-H), 7.19 (dd, H-3 ), 3.83–3.86 (m, 1H, H-5 ), 3.74 (t, 1H, J ¼ 10.2 Hz, H-2 ),
1
1
H, J ¼ 8.2, 1.1 Hz, Ar-H), 6.62 (d, 1H, J ¼ 2.2 Hz, Ar-H), 6.52 (d, 2.19, 2.13 (s, each 3H, 2 ꢃ CH
3
CO), 1.36 (t, 3H, J ¼ 6.1 Hz, CH
3
);
0
13
H, J ¼ 2.2 Hz, Ar-H), 5.56 (d, 1H, J ¼ 1.6 Hz, H-1 ), 5.52 (dd, 1H,
C NMR (CDCl ): d 181.2, 171.2, 170.0, 163.7, 162.7, 157.6,
3
0
0
J ¼ 10.4 Hz, 3.8 Hz, H-3 ), 5.44 (dd, 1H, J ¼ 3.3 Hz, 1.7 Hz, H-2 ), 156.2, 135.3, 126.0, 124.2, 120.7, 117.8, 105.1, 99.1, 95.7, 95.1,
0
0
5
(
.18 (t, 1H, J ¼ 9.9 Hz, H-4 ), 3.94–3.97 (m, 1H, H-5 ), 2.74–2.77 71.8, 71.1, 70.1, 69.6, 31.0, 21.0, 20.9, 17.7; HRESIMS calcd for
m, 2H, COCH ), 2.53–2.55 (m, 2H, COCH ), 2.51 (s, 3H, Ar- 10 457.1135; found 457.1141.
2
2
23 21
C H O
0
0
CH ), 2.20, 2.19, 2.09 (s, each 3H, each COCH ), 1.24 (d, 3H, J ¼
1-Hydroxy-3-(2 ,3 -di-O-acetyl-a-L-rhamnopyranosyl)-6-methyl-
3
3
1
3
6
1
9
1
.6 Hz, CH ); C NMR (CDCl ): d 206.1, 181.0, 171.9, 170.3, 9H-xanthen-9-one (2). White solid in 81.6% yield; R 0.67 (2 : 1,
3
3
f
ꢀ
25
D
70.1, 163.7, 157.6, 156.3, 147.1, 125.8, 118.4, 117.6, 105.1, 99.0, petroleum ether–acetone); m.p. 191–192 C; [a] ꢁ122.8 (c 0.11,
1
5.6, 95.0, 70.9, 69.5, 68.5, 67.9, 37.8, 29.8, 28.0, 22.1, 20.9, 20.8, CHCl
3
); H NMR (CDCl
3
): d 12.89 (s, 1H, OH), 8.11 (d, 1H, J ¼ 8.2
7.5; HRESIMS calcd for C29
1
H
31
0
O
12 571.1816; found 571.1818.
Hz, Ar-H), 7.23 (brs, 1H, Ar-H), 7.18 (dd, 1H, J ¼ 8.3 Hz, 1.0 Hz,
0
0
-Hydroxy-6-(2 ,3 -di-O-acetyl-4 -levulinyl-a-L-rhamnopyranosyl)- Ar-H), 6.61 (d, 1H, J ¼ 2.3 Hz, Ar-H), 6.52 (d, 1H, J ¼ 2.2 Hz, Ar-
0
3
R
-methyl-9H-xanthen-9-one (37). Yellow solid in 84.6% yield; H), 5.55 (d, 1H, J ¼ 1.8 Hz, H-1 ), 5.43 (dd, 1H, J ¼ 3.7 Hz, 1.9 Hz,
ꢀ
0
0
0
f
0.47 (1 : 1, petroleum ether–EtOAc); m.p. 169–170
C
H-2 ), 5.32 (dd, 1H, J ¼ 10.0 Hz, 3.7 Hz, H-3 ), 3.83–3.86 (m, 1H,
2
5
1
0
[
a] ꢁ118.2 (c 0.10, CHCl ); H NMR (CDCl ): d 12.59 (s, 1H, H-5 ), 3.74 (t, 1H, J ¼ 9.6 Hz, H-4 ), 2.51 (s, 3H, Ar-CH ), 2.19,
D
3
3
3
13
OH), 8.21 (d, 1H, J ¼ 8.8 Hz, Ar-H), 7.13 (d, 1H, J ¼ 1.7 Hz, Ar-H), 2.13 (s, each 3H, each COCH ), 1.36 (d, 3H, J ¼ 6.4 Hz, CH );
C
3
3
7
.10 (dd, 1H, J ¼ 8.8 Hz, 1.9 Hz, Ar-H), 6.73 (d, 1H, J ¼ 2.2 Hz, NMR (CDCl ): d 181.0, 171.2, 170.0, 163.6, 162.5, 157.6, 156.3,
3
0
Ar-H), 6.63 (d, 1H, J ¼ 2.2 Hz, Ar-H), 5.62 (d, 1H, J ¼ 1.6 Hz, H-1 ), 147.0, 125.7, 118.4, 117.6, 105.0, 98.9, 95.7, 95.1, 71.8, 71.1, 70.0,
0
5
1
5
.55 (dd, 1H, J ¼ 10.1 Hz, 3.5 Hz, H-3 ), 5.47 (dd, 1H, J ¼ 3.5 Hz, 69.7, 22.1, 21.0, 20.9, 17.7; HRESIMS calcd for C24
23 10
H O
0
0
.7 Hz, H-2 ), 5.21 (t, 1H, J ¼ 10.0 Hz, H-4 ), 3.94–3.97 (m, 1H, H- 471.1291; found 471.1300.
0
0
0
), 2.75–2.77 (m, 2H, COCH
2
), 2.53–2.55 (m, 2H, COCH
2
), 2.51
1-Hydroxy-6-(2 ,3 -di-O-acetyl-a-L-rhamnopyranosyl)-3-methyl-
0.35 (3 : 1,
(s, 3H, Ar-CH
3
), 2.22, 2.19, 2.11 (s, each 3H, each COCH
3
), 1.25 9H-xanthen-9-one (3). White solid in 80.8% yield; R
f
1
3
ꢀ
25
D
(
d, 3H, J ¼ 6.6 Hz, CH ); C NMR (CDCl ): d 206.0, 180.8, 171.7, petroleum ether–acetone); m.p. 181–182 C; [a] ꢁ112.5 (c 0.10,
3
3
1
1
1
2
5
70.3, 170.0, 161.5, 161.0, 157.6, 156.3, 148.5, 127.7, 115.9, CHCl ); H NMR (CDCl ): d 12.60 (s, 1H, OH), 8.20 (d, 1H, J ¼ 8.8
3
3
13.9, 111.5, 107.4, 106.8, 103.4, 95.5, 70.7, 69.4, 68.3, 67.9, 37.7, Hz, Ar-H), 7.12 (d, 1H, J ¼ 2.2 Hz, Ar-H), 7.09 (dd, 1H, J ¼ 8.8 Hz,
9.7, 27.9, 22.6, 20.9, 20.8, 17.4; HRESIMS calcd for C29
71.1816; found 571.1809.
31
H O12 2.2 Hz, Ar-H), 6.73 (s, 1H, Ar-H), 6.62 (s, 1H, Ar-H), 5.60 (d, 1H, J
0
0
¼ 1.6 Hz, H-1 ), 5.46 (dd, 1H, J ¼ 3.4 Hz, 1.8 Hz, H-2 ), 5.36 (dd,
0
0
0
0
0
1
-Hydroxy-3-(2 ,3 -di-O-acetyl-4 -levulinyl-a-L-rhamnopyranosyl)- 1H, J ¼ 9.8 Hz, 3.5 Hz, H-3 ), 3.83–3.88 (m, 1H, H-5 ), 3.76 (t, 1H,
0
9H-thioxanthen-9-one (38). Yellow solid in 85.9% yield; R
f
0.31 J ¼ 9.7 Hz, H-4 ), 2.43 (s, 3H, Ar-CH
3
), 2.21, 2.14 (s, each 3H,
ꢀ
25
D
13
(2 : 1, petroleum ether–EtOAc); m.p. 156–157 C; [a]
ꢁ148.5 (c each COCH
3
), 1.38 (d, 3H, J ¼ 6.1 Hz, CH
3 3
); C NMR (CDCl ): d
1
0
.12, CHCl ); H NMR (CDCl ): d 8.56 (dd, 1H, J ¼ 7.1 Hz, 1.1 Hz, 181.0, 171.1, 170.0, 161.6, 161.4, 157.7, 156.3, 148.5, 127.8,
3
3
Ar-H), 7.62 (td, 1H, J ¼ 7.1 Hz, 1.1 Hz, Ar-H), 7.52 (d, 1H, J ¼ 7.1 115.8, 114.0, 111.4, 107.4, 106.8, 103.6, 95.6, 71.6, 70.9, 70.0,
Hz, Ar-H), 7.48 (t, 1H, J ¼ 7.1 Hz, Ar-H), 6.77 (d, 1H, J ¼ 2.7 Hz, 69.6, 22.6, 21.0, 20.8, 17.6; HRESIMS calcd for C H O
2
4
23 10
0
Ar-H), 6.65 (d, 1H, J ¼ 2.7 Hz, Ar-H), 5.57 (d, 1H, J ¼ 1.1 Hz, H-1 ), 471.1291; found 471.1300.
0
0 0
1-Hydroxy-3-(2 ,3 -di-O-acetyl-a-L-rhamnopyranosyl)-9H-thioxan-
5
1
5
2
.51 (dd, 1H, J ¼ 9.9 Hz, 3.3 Hz, H-3 ), 5.42 (dd, 1H, J ¼ 3.3 Hz,
0
0
.6 Hz, H-2 ), 5.18 (t, 1H, J ¼ 9.9 Hz, H-4 ), 3.93–3.96 (m, 1H, H- then-9-one (4). Yellow solid in 82.3% yield; R
f
0.28 (3 : 1, petro-
0
ꢀ
25
), 2.74–2.77 (m, 2H, COCH
2
), 2.52–2.55 (m, 2H, COCH
2
), 2.20, leum ether–acetone); m.p. 186–187 C; [a]
D
ꢁ138.4 (c 0.10,
1
.18, 2.09 (s, each 3H, 3 ꢃ CH
3
CO), 1.24 (t, 3H, J ¼ 6.0 Hz, CH
3
); CHCl
3
); H NMR (CDCl
3
): d 8.55 (dd, 1H, J ¼ 8.2 Hz, 1.1 Hz, Ar-
1
3
C NMR (CDCl ): d 206.1, 184.5, 171.9, 170.3, 170.1, 167.4, H), 7.61 (td, 1H, J ¼ 8.3 Hz, 1.7 Hz, Ar-H), 7.51 (d, 1H, J ¼ 8.2 Hz,
3
1
1
1
5
40.6, 137.3, 132.9, 129.4, 128.3, 126.5, 125.5, 110.7, 103.3, Ar-H), 7.47 (td, 1H, J ¼ 8.2 Hz, 1.1 Hz, Ar-H), 6.76 (d, 1H, J ¼ 2.2
01.9, 95.5, 70.9, 69.5, 68.4, 68.0, 37.8, 29.8, 28.0, 20.9, 20.8, Hz, Ar-H), 6.65 (d, 1H, J ¼ 2.2 Hz, Ar-H), 5.55 (d, 1H, J ¼ 1.7 Hz,
0
0
7.5; HRESIMS calcd for C28
95.1262.
H
28
O
11SNa 595.1250; found H-1 ), 5.42 (dd, 1H, J ¼ 3.3 Hz, 1.7 Hz, H-2 ), 5.32 (dd, 1H, J ¼ 9.9
0
0
Hz, 3.3 Hz, H-3 ), 3.82–3.85 (m, 1H, H-5 ), 3.73 (t, 1H, J ¼ 10.2
0
General procedure for the preparation of 1–4. To a stirred Hz, H-4 ), 2.19, 2.13 (s, each 3H, 2 ꢃ COCH
3
), 1.36 (t, 3H, J ¼ 6.1
1
3
3 3
solution of the different yellow compounds 35–38 (1 eq) in Hz, CH ); C NMR (CDCl ): d 184.4, 171.2, 170.0, 167.3, 160.7,
CH
2
Cl
2
and CH
3
OH (v/v ¼ 1/1) was added NH
2
NH
2
–HOAc (10 140.5, 137.3, 132.8, 129.3, 128.3, 126.5, 125.5, 110.6, 103.4,
36100 | RSC Adv., 2015, 5, 36092–36103
This journal is © The Royal Society of Chemistry 2015