Journal of Natural Products
Article
data for the minor diastereoisomer, δH (500 MHz, CDCl3) 0.99 (3H,
d, J 7.0 Hz, H-8′), 2.00−2.18 (1H, m obsc, H-6′), 2.91 (1H, dd, J 8.5,
16.0 Hz, Ha-4′), 3.27 (1H, dd, J 8.5, 16.0 Hz, Hb-4′), 3.66−3.74 (2H,
m obsc, Ha-7′ and Hb-7′), 3.76 (3H, s, H-2′), 3.81 (3H, s, H-3′), 3.84
(1H, d, J 4.0 Hz, H-12a), 4.18 (1H, d, J 12.0 Hz, Ha-6), 4.62 (1H, dd,
J 3.0, 12.0 Hz, Hb-6), 4.78 (dd, J 4.5, 8.5 Hz, H-5′), 4.93 (1H, ddd, J
1.0, 3.0, 4.0 Hz, H-6a), 6.45 (1H, s, H-4), 6.47 (1H, d, J 8.5 Hz, H-
10), 6.77 (1H, s, H-1), 7.83 (1H, d, J 8.5 Hz, H-11); δC (125 MHz,
CDCl3) 12.7 (C-8′), 30.7 (C-4′), 41.1 (C-6′), 44.8 (C-12a), 56.0 (C-
3′), 56.5 (C-2′), 65.2 (C-7′), 65.9 (C-6), 72.4 (C-6a), 88.9 (C-5′),
101.1 (C-4), 104.9 (C-1a), 105.1 (C-10), 110.5 (C-1), 113.2 (C-11a),
113.5 (C-8), 130.1 (C-11), 144.0 (C-2), 147.5 (C-4a), 149.6 (C-3),
158.1 (C-7a), 167.1 (C-9), 189.1 (C-12); HRESIMS m/z 435.1403
[M + Na]+ (calcd for C23H24O7Na, m/z 435.1414).
s, H-1); 13C NMR (125 MHz, acetone-d6) δ 17.4 (C-8′), 32.7 (C-4′),
38.5 (C-12a), 55.9 (C-3′), 56.8 (C-2′), 66.5 (C-6), 67.6 (C-12), 71.2
(C-6a), 86.8 (C-5′), 101.3 (C-4), 102.3 (C-10), 111.5 (C-7′), 111.6
(C-1a), 112.8 (C-8), 114.6 (C-1), 117.6 (C-11a), 129.6 (C-11), 144.4
(C-2), 145.5 (C-6′), 150.2 (C-3), 150.3 (C-4a), 150.6 (C-7a), 161.9
(C-9); HRESIMS m/z 419.1449 [M + Na]+ (calcd for C20H24O6Na,
m/z 419.1465).
(6aS,12S,12aR,5′R)-12-Deoxo-12-hydroxyamorphigenin (11). 11
was prepared from 3 (20 mg, 0.048 mmol) by GP1 and obtained as a
white solid (17.7 mg, 88%): [α]20 −164 (c 0.1, acetone); IR νmax
D
3600−3300, 1620, 1515, 1465, 1220, 1194, 1131, 1093, 1039, 984,
1
787 cm−1; H NMR (500 MHz, acetone-d6) δ 3.00 (1H, dd, J 8.5,
15.5 Hz, Ha-4′), 3.28 (1H, dd, J 8.5, 15.5 Hz, Hb-4′), 3.44 (1H, app t,
J 4.5 Hz, H-12a), 3.70 (3H, s, H-2′), 3.74 (3H, s, H-3′), 4.17 (1H, J
3.0, 9.5 Hz, Ha-6), 4.18 (1H, d, J 14.0 Hz, Ha-8′), 4.19 (1H, d, J 14.0
Hz, Hb-8′), 4.50 (1H, d, J 4.0 Hz, OH-12), 4.59 (1H, app t, J 9.5 Hz,
Hb-6), 4.80 (1H, ddd, J 3.0, 4.5, 9.5 Hz, H-6a), 5.16 (1H, dd, J 4.0, 4.5
Hz, H-12), 5.17 (1H, s, Ha-7′), 5.19 (1H, s, Hb-7′), 5.30 (1H, app t, J
8.5 Hz, H-5′), 6.33 (1H, d, J 8.0 Hz, H-10), 6.37 (1H, s, H-4), 7.10
(1H, d, J 8.0 Hz, H-11), 7.17 (1H, s, H-1); 13C NMR (125 MHz,
acetone-d6) δ 33.3 (C-4′), 38.5 (C-12a), 55.9 (C-3′), 56.8 (C-2′),
62.3 (C-8′), 66.5 (C-6), 67.6 (C-12), 71.2 (C-6a), 84.6 (C-5′), 101.3
(C-4), 102.3 (C-10), 109.6 (C-7′), 111.6 (C-1a), 112.9 (C-8), 114.6
(C-1), 117.7 (C-11a), 129.6 (C-11), 144.4 (C-2), 150.2 (C-6′), 150.2
(C-3), 150.3 (C-4a), 150.6 (C-7a), 161.8 (C-9); HRESIMS m/z
435.1402 [M + Na]+ (calcd for C23H24O7Na, m/z 435.1414).
(6aS,12S,12aR,5′R)-12-Deoxo-12-hydroxydalpanol (12).27 12
was prepared from 4 (20 mg, 0.049 mmol) by GP1 and obtained
as a white solid (18.5 mg, 92%): [α]20D −120 (c 0.1, acetone); IR νmax
3600−3300, 1617, 1518, 1505, 1483, 1467, 1240, 1220, 1192, 1131,
(6aR,12aR,5′R)-Rotenolone (7). 7 was prepared by modifying a
literature procedure.50 A solution of K2Cr2O7 (2.8 g, 9.45 mmol) in
H2O (40 mL) was added dropwise over 10 min to a solution of 1 (4.0
g, 10.15 mmol) in AcOH (80 mL) at 60 °C. The mixture was stirred
for 0.5 h, then cooled to rt and stirred for a further 18 h. The dark
green mixture was poured onto crushed ice (400 mL), and the
resulting suspension was stirred for 1 h while an off-white precipitate
formed. The precipitate was collected by filtration, washed thoroughly
with H2O (200 mL), dried in vacuo, and purified by flash
chromatography (SiO2, 2:1 hexanes/EtOAc) to give 7 as a white
solid (3.42 g, 82%): [α]20 −176 (c 0.1, CHCl3) [lit.50 [α]16 −189
D
D
(c 2.0, CHCl3)]; IR νmax 3600−3300, 1673, 1607, 1508, 1455, 1331,
1
1258, 1216, 1154, 1085, 1023, 905, 816 cm−1; H NMR (500 MHz,
CDCl3) δ 1.76 (3H, s, H-8′), 2.93 (1H, dd, J 8.0, 16.0 Hz, Ha-4′),
3.29 (1H, dd, J 8.0, 16.0 Hz, Hb-4′), 3.72 (3H, s, H-2′), 3.82 (3H, s,
H-3′), 4.47 (1H, s, OH-12a), 4.49 (1H, d, J 11.5 Hz, Ha-6), 4.58 (1H,
dd, J 1.0, 2.5 Hz, H-6a), 4.59 (1H, dd, J 2.5, 11.5 Hz, Hb-6), 4.93 (1H,
s, Ha-7′), 5.06 (1H, s, Hb-7′), 5.23 (1H, app t, J 8.0 Hz, H-5′), 6.48
(1H, s, H-4), 6.53 (1H, d, J 8.5 Hz, H-10), 6.55 (1H, s, H-1), 7.82
(1H, d, J 8.5 Hz, H-11); 13C NMR (125 MHz, CDCl3) δ 17.2 (C-8′),
31.3 (C-4′), 56.0 (C-3′), 56.5 (C-2′), 64.0 (C-6), 67.7 (C-12a), 76.2
(C-6a), 88.1 (C-5′), 101.2 (C-4), 105.5 (C-10), 108.9 (C-1a), 109.4
(C-1), 111.9 (C-11a), 112.9 (C-7′), 113.3 (C-8), 130.2 (C-11), 143.0
(C-6′), 144.1 (C-2), 148.5 (C-4a), 151.2 (C-3), 157.8 (C-7a), 168.2
(C-9), 191.2 (C-12); HRESIMS m/z 433.1241 [M + Na]+ (calcd for
C23H22O7Na, m/z 433.1258).
1
1078, 1039, 956, 789 cm−1; H NMR (500 MHz, acetone-d6) δ 1.20
(3H, s, H-7′), 1.24 (3H, s, H-8′), 2.98 (1H, dd, J 8.5, 13.5 Hz, Ha-4′),
3.10 (1H, dd, J 8.5, 13.5 Hz, Hb-4′), 3.43 (1H, app t, J 5.0 Hz, H-
12a), 3.70 (3H, s, H-2′), 3.74 (3H, s, H-3′), 4.17 (1H, dd, J 4.0, 10.0
Hz, Ha-6), 4.44 (1H, s, OH-12), 4.59 (1H, app t, J 8.5 Hz, H-5′), 4.60
(1H, app t, J 8.5 Hz, Hb-6), 4.80 (1H, ddd, J 4.0, 5.0, 10.0 Hz, H-6a),
5.11 (1H, dd, J 4.0, 5.0 Hz, H-12), 6.26 (1H, d, J 8.0 Hz, H-10), 6.37
(1H, s, H-4), 7.05 (1H, d, J 8.0 Hz, H-11), 7.16 (1H, s, H-1); 13C
NMR (125 MHz, acetone-d6) δ 25.6 (C-7′), 26.0 (C-8′), 28.5 (C-4′),
38.6 (C-12a), 55.9 (C-3′), 56.8 (C-2′), 66.5 (C-6), 67.6 (C-12), 71.1
(C-6a), 71.5 (C-6′), 90.9 (C-5′), 101.3 (C-4), 102.2 (C-10), 111.7
(C-1a), 113.7 (C-8), 114.6 (C-1), 117.3 (C-11a), 129.3 (C-11), 144.4
(C-2), 150.2 (C-4a), 150.3 (C-7a), 150.5 (C-3), 162.2 (C-9);
HRESIMS m/z 437.1557 [M + Na]+ (calcd for C23H26O7Na, m/z
437.1571).
(6aS,12aS)-2′-Oxorot-3′-enonic Acid (9).45 9 was prepared from 1
(200 mg, 0.508 mmol) by GP3 and obtained as a yellow solid (44 mg,
21%): [α]20 +34 (c 0.1, CHCl3) [lit.45 [α]25 +38 (c 0.1, CHCl3)];
D
D
IR νmax 3400−3100, 1675, 1579, 1547, 1513, 1444, 1347, 1286, 1259,
1
1216, 1196, 1051, 817 cm−1; H NMR (500 MHz, CDCl3) δ 1.86
(3H, s, H-5′), 3.75 (3H, s, H-2″), 3.81 (3H, s, H-3″), 3.84 (1H, d, J
4.0 Hz, H-12a), 3.87 (1H, d, J 13.5 Hz, Ha-1′), 4.22 (1H, d, J 12.0 Hz,
Ha-6), 4.23 (1H, d, J 13.5 Hz, Hb-1′), 4.64 (1H, dd, J 3.5, 12.0 Hz,
Hb-6), 4.95 (1H, ddd, J 1.0, 3.5, 4.0 Hz, H-6a), 6.00 (1H, s, Ha-4′),
6.42 (1H, s, H-4), 6.59 (1H, s, Hb-4′), 6.63 (1H, d, J 8.5 Hz, H-10),
6.74 (1H, s, H-1), 7.81 (1H, d, J 8.5 Hz, H-11), 8.97 (1H, s, OH-9);
13C NMR(125 MHz, CDCl3) δ 17.5 (C-5′), 32.3 (C-1′), 44.4 (C-
12a), 56.1 (C-3″), 56.4 (C-2″), 66.5 (C-6), 72.6 (C-6a), 100.9 (C-4),
104.7 (C-1a), 108.5 (C-8), 110.4 (C-1), 112.6 (C-10), 112.8 (C-11a),
128.7 (C-11), 130.3 (C-4′), 143.7 (C-3′), 144.1 (C-2), 147.5 (C-4a),
149.7 (C-3), 159.1 (C-7a), 163.9 (C-9), 189.4 (C-12), 203.7 (C-2′);
HRESIMS m/z 433.1239 [M + Na]+ (calcd for C23H22O7Na, m/z
433.1258).
(6aS,12S,12aR,5′R,6′R)- and (6aS,12S,12aR,5′R,6′S)-12-Deoxo-
12-hydroxyamorphigenol (13). 13 was prepared from 6 (20.0 mg,
0.047 mmol) by GP1, and the mixture of diastereoisomers 13 was
obtained as a white solid (17.9 mg, 89%, dr 63:37 unassigned): IR
νmax 3600−3200, 1621, 1513, 1464, 1261, 1218, 1195, 1132, 1094,
1038, 987, 787 cm−1; NMR data for the major diastereoisomer, δH
(500 MHz, acetone-d6) 1.15 (3H, s, H-8′), 2.98 (1H, dd, J 6.5, 15.5
Hz, Ha-4′), 3.17 (1H, dd, J 6.5, 15.5 Hz, Hb-4′), 3.43 (1H, app t, J 6.5
Hz, H-12a), 3.57 (1H, dd, J 5.5, 11.0 Hz, Ha-7′), 3.68 (1H, dd, J 5.5,
11.0 Hz, Hb-7′), 3.70 (3H, s, H-2′), 3.74 (3H, s, H-3′), 4.16 (1H, dd,
J 3.0, 10.0 Hz, Ha-6), 4.44 (1H, d, J 4.0 Hz, OH-12), 4.60 (1H, app t,
J 10.0 Hz, Hb-6), 4.81 (1H, m obsc, H-6a), 4.83 (1H, app t, J 6.0 Hz,
H-5′), 5.12 (1H, dd, J 4.0, 6.5 Hz, H-12), 6.27 (1H, d, J 8.0 Hz, H-
10), 6.37 (1H, s, H-4), 7.06 (1H, d, J 8.0 Hz, H-11), 7.16 (1H, s, H-
1); δC (125 MHz, acetone-d6) 19.7 (C-8′), 28.0 (C-4′), 38.6 (C-12a),
55.9 (C-3′), 56.8 (C-2′), 66.5 (C-6), 67.6 (C-12), 68.1 (C-7′), 71.1
(C-6a), 73.8 (C-6′), 86.7 (C-5′), 101.4 (C-4), 102.3 (C-10), 111.7
(C-1a), 113.7 (C-8), 114.6 (C-1), 117.3 (C-11a), 129.3 (C-11), 144.4
(C-2), 150.2 (C-3), 150.3 (C-4a), 150.5 (C-7a), 162.1 (C-9); NMR
data for the minor diastereoisomer, δH (500 MHz, acetone-d6) 1.16
(3H, s, H-8′), 2.98 (1H, dd, J 6.5, 15.5 Hz, Ha-4′), 3.18 (1H, dd, J 6.5,
15.5 Hz, Hb-4′), 3.43 (1H, app t, J 6.5 Hz, H-12a), 3.49 (1H, dd, J
5.5, 11.0 Hz, Ha-7′), 3.65 (1H, dd, J 5.5, 11.0 Hz, Hb-7′), 3.70 (3H, s,
H-2′), 3.74 (3H, s, H-3′), 4.16 (1H, dd, J 3.0, 10.0 Hz, Ha-6), 4.42
(1H, d, J 4.0 Hz, OH-12), 4.60 (1H, app t, J 10.0 Hz, Hb-6), 4.80
(6aS,12S,12aR,5′R)-12-Deoxo-12-hydroxyrotenone (10).49 10
was prepared from 1 (1.0 g, 2.54 mmol) by GP1 and obtained as a
white solid (921 mg, 92%): [α]20 −150 (c 0.1, acetone); IR νmax
D
3600−3300, 1619, 1512, 1479, 1463, 1217, 1194, 1131, 1091, 1037,
1
799 cm−1; H NMR (500 MHz, acetone-d6) δ 1.76 (3H, s, H-8′),
2.88 (1H, dd, J 9.0, 15.5 Hz, Ha-4′), 3.22 (1H, dd, J 9.0, 15.5 Hz, Hb-
4′), 3.44 (1H, app t, J 4.5 Hz, H-12a), 3.70 (3H, s, H-2′), 3.74 (3H, s,
H-3′), 4.17 (1H, dd, J 3.0, 10.0 Hz, Ha-6), 4.48 (1H, d, J 4.0 Hz, OH-
12), 4.61 (1H, app t, J 10.0 Hz, Hb-6), 4.81 (1H, ddd, J 3.0, 4.5, 10.0
Hz, H-6a), 4.88 (1H, s, Ha-7′), 5.06 (1H, s, Hb-7′), 5.12 (1H, dd, J
4.0, 4.5 Hz, H-12), 5.16 (1H, app t, J 9.0 Hz, H-5′), 6.32 (1H, d, J 8.0
Hz, H-10), 6.37 (1H, s, H-4), 7.10 (1H, d, J 8.0 Hz, H-11), 7.17 (1H,
K
J. Nat. Prod. XXXX, XXX, XXX−XXX