The Journal of Organic Chemistry
Article
5
0
.8 Hz, J = 1.5 Hz), 7.52 (dd, 0.74H, J = 5.8 Hz, J = 1.6 Hz), 6.70* (s,
.25H), 6.68 (s, 0.75H), 6.51 (m, 1H), 6.28 (m, 1H), 5.16* (t, 0.24H,
Hz), 5.37 (t, 0.83H, J = 1.8 Hz), 3.76 (s, 2.52H), 3.72 (s, 0.40H), 3.18
(d, 1H, J = 16.6 Hz), 3.17 (d, 1H, J = 16.6 Hz), 2.35* (s, 0.43H), 2.34
J = 1.7 Hz), 5.09 (t, 0.76H, J = 1.7 Hz), 2.95* (d, 0.25H, J = 16.4 Hz),
(s, 3H), 2.33 (s, 2. 76H). 13C NMR (100 MHz, CDCl ): δ 186.0,
3
2
0
0
.86 (d, 0.75H, J = 16.4 Hz), 2.69* (d, 0.25H, J = 16.4 Hz), 2.52 (d,
.78H, J = 16.4 Hz), 2.36* (s, 0.8H), 2.35 (s, 2.23H), 2.34* (s,
.76H), 2.33 (s, 2.35H), 1.51 (s, 2.26H), 1.33* (s, 0.74H). C NMR
171.1, 169.3, 168.6, 159.6, 150.8, 149.6, 148.4, 124.0, 118.2, 116.1,
111.2, 83.0, 82.5, 53.8, 40.9, 21.9, 21.0. HRMS-ESI (m/z): calcd for
13
+
C H O Na [M + Na] 383.0737, found 383.0742. IR (neat): 3365,
18
16
8
(
100 MHz, CDCl ): δ 188.0, 187.9*, 171.8*, 171.7, 169.7*, 169.6,
3122, 3017, 2956, 2923, 2852, 1794, 1761, 1691, 1625, 1564, 1436,
3
−1
1
1
4
59.5*, 159.4, 152.1*, 151.6, 149.7*, 149.6, 148.3*, 148.2, 123.9,
23.7*, 117.4*, 117.35, 116.4, 116.2*, 111.0, 85.9, 85.2*, 80.5*, 80.4,
5.4*, 43.6, 21.9, 21.1, 21.0*, 19.2. HRMS-ESI (m/z): calcd for
1370, 1266, 1198, 1093, 1024, 883, 841, 757, 580 cm . * = minor
diastereomer.
Methyl 5-Acetoxy-7-(acetoxymethyl)-4-oxo-2-(5-oxo-2,5-dihy-
drofuran-2-yl)chromane-2-carboxylate (6l). This compound was
prepared from 5l and purified by gel column chromatography (PE/
EtOAc 2/1 v/v as eluent) to give an inseparable mixture of
diastereomers of 6l (20:1) as a colorless gum (74 mg, 88%). Anal.
+
C H O [M + H] 317.1020, found 317.1029. IR (neat): 3444, 2917,
1
6
1
7
17
6
757, 1687, 1623, 1563, 1455, 1340, 1267, 1198, 1076, 1018, 890, 832,
−1
92 cm . * = minor diastereomer.
2
-Methyl-4-oxo-2-(5-oxo-2,5-dihydrofuran-2-yl)chromane-5,7-
1
diyl Diacetate (6h). This compound was prepared from 5h and
purified by gel column chromatography (PE/EtOAc 1/1 v/v as
eluent) to give an inseparable mixture of diastereomers of 6h (20:1) as
a colorless gum (58 mg, 81%). Anal. Calcd for C H O : C, 60.00; H,
Calcd for C H O : C, 57.42; H, 4.34. Found: C, 57.21; H, 4.42. H
20
18 10
NMR (400 MHz, CDCl ): δ 7.51 (dd, 1H, J = 5.8 Hz, J = 1.6 Hz),
3
6.90 (d, 1H, J = 0.4 Hz), 6.69 (d, 1H, J = 0.8 Hz), 6.35 (dd, 1H, J = 6.0
Hz, J = 2.0 Hz), 5.39 (t, 1H, J = 1.8 Hz), 5.07 (s, 2H), 3.78 (s, 3H),
3.22 (d, 1H, J = 16.6 Hz), 3.04 (d, 1H, J = 16.6 Hz), 2.36 (s, 3H), 2.16
1
8
16
8
1
4
.48. Found: C, 59.62; H, 4.31. H NMR (400 MHz, CDCl ): δ 7.52
3
(s, 3H). 13C NMR (100 MHz, CDCl ): δ 186.0, 171.1, 170.5, 169.3,
(
dd, 1H, J = 5.6 Hz, J = 1.6 Hz), 6.69 (d, 1H, J = 2.0 Hz), 6.50 (d, 1H,
3
J = 2.0 Hz), 6.27 (dd, 1H, J = 6.0 Hz, J = 2.0 Hz), 5.08 (t, 1H, J = 1.6
Hz), 2.89 (d, 1H, J = 16.0 Hz), 2.52 (d, 1H, J = 16.4 Hz), 2.33 (s, 3H),
168.5, 159.9, 150.7, 150.1, 145.5, 124.3, 115.9, 114.3, 112.9, 83.0, 82.8,
64.5, 54.0, 41.2, 21.1, 20.9. HRMS-ESI (m/z): calcd for C H O [M
2
0
19 10
2
1
1
.28 (s, 3H), 1.51 (s, 3H). 13C NMR (100 MHz, CDCl ): δ 187.4,
+ H] 419.0973, found 419.0977. IR (neat): 3423, 2921, 2857,
2358,1792, 1746, 1628, 1430, 1383, 1155, 1068, 1026, 669, 647, 619
cm .
Methyl 5-Methoxy-7-methyl-4-oxo-2-(5-oxo-2,5-dihydrofuran-2-
+
3
71.6, 169.1, 167.9, 160.2, 156.2, 151.5, 150.8, 124.0, 111.2, 110.5,
09.1, 85.8, 80.9, 43.4, 21.2, 21.10, 20.98. HRMS-ESI (m/z): calcd for
−1
+
C H O [M + H] 361.0918, found 361.0923. IR (neat): 3366, 3096,
1
8
17
8
3
1
023, 2926, 2850, 2256, 1762, 1692, 1618, 1578, 1433, 1369, 1269,
yl)chromane-2-carboxylate (6m). This compound was prepared from
5m and purified by gel column chromatography (PE/EtOAc 2/1 v/v
as eluent) to give an inseparable mixture of diastereomers of 6m (1:1)
−1
189, 1130, 1075, 1026, 892, 831, 756, 663, 583 cm .
5-Acetoxy-2-methyl-4-oxo-2-(5-oxo-2,5-dihydrofuran-2-yl)-
(
chroman-7-yl)methyl Acetate (6i). This compound was prepared
from 5i and purified by gel column chromatography (PE/EtOAc 2/1
v/v as eluent) to give an inseparable mixture of diastereomers of 6i
as a colorless gum (40 mg, 60%). Anal. Calcd for C17
H, 4.85. Found: C, 61.07; H, 4.57. H NMR (400 MHz, CDCl ): δ
H
16
O
7
: C, 61.45;
1
3
7.60 (dd, 0.70H, J = 5.6 Hz, J = 1.2 Hz), 7.49* (dd, 0.42H, J = 5.6 Hz,
J = 1.2 Hz), 6.51 (s, 0.4H), 6.43 (s, 0.4H), 6.34 (s, 1H), 6.33* (dd,
0.49H, J = 5.6 Hz, J = 2.0 Hz), 6.29 (dd, 0.51H, J = 5.6 Hz, J = 2.0
Hz), 5.40* (t, 0.44H, J = 1.6 Hz), 5.37 (t, 0.49H, J = 1.6 Hz), 3.88 (s,
2.57H), 3.86* (s, 0.54H), 3.76* (s, 1.45H), 3.71 (s, 1.56H), 3.23−2.98
(
3:1) as a colorless gum (52 mg, 70%). Anal. Calcd for C H O : C,
19 18 8
6
0.96; H, 4.85. Found: C, 60.64; H, 4.57. 1H NMR (400 MHz,
CDCl ): δ 7.57* (dd, 0.32H, J = 5.6 Hz, J = 1.2 Hz), 7.53 (dd, 0.71H,
J = 5.6 Hz, J = 1.2 Hz), 6.87* (s, 0.25H), 6.85 (s, 0.74H), 6.67* (s,
3
13
0
.23H), 6.66 (s, 0.77H), 6.30 (dd, 1H, J = 6.0 Hz, J = 2.0 Hz), 5.17*
(m, 2H), 2.34* (s, 1.35H), 2.32 (s, 1.64H). C NMR (100 MHz,
CDCl ): δ 186.2*, 185.7, 171.2*, 171.1, 168.8*, 168.2, 160.4*, 160.24,
(
s, 0.22H), 5.10 (t, 0.77H, J = 1.6 Hz), 5.07 (m, 2H), 2.97* (d, 0.23H,
3
J = 16.0 Hz), 2.91 (d, 0.77H, J = 16.4 Hz), 2.72* (d, 0.22H, J = 16.4
Hz), 2.55 (d, 0.80H, J = 16.4 Hz), 2.38* (s, 0.67H), 2.37 (s, 2.24H),
160.18*, 160.1, 150.8, 150.7*, 148.7*, 148.4, 123.79*, 123.75, 110.3*,
110.2, 108.5, 108.3*, 106.02, 106.01*, 83.7, 83.1*, 82.6, 82.2*, 56.0,
13
2
.16 (s, 3H), 1.53 (s, 2.36H), 1.35* (s, 0.63H). C NMR (100 MHz,
55.8*, 53.6*, 53.4, 41.5*, 41.3, 22.4, 22.3*. HRMS-ESI (m/z): calcd
+
CDCl ): δ 187.9, 171.6, 170.4, 169.5, 159.7, 151.4, 150.0, 145.3, 124.1,
for C17H
O
17
7
[M + H] 333.0969, found 333.0966. IR (neat): 3357,
3
1
15.0, 114.6, 112.7, 85.8, 80.7, 64.5, 43.7, 21.04, 21.00, 20.8. HRMS-
2925, 2854, 2373, 1792, 1743, 1638, 1606, 1571, 1461, 1416, 1219,
+
−1
ESI (m/z): calcd for C H O [M + H] 375.1074, found 375.1078.
1160, 1116, 1044, 882, 826, 736, 702, 628 cm . * = diastereomer.
19
19
8
IR (neat): 3396, 2956, 2922, 2851, 1750, 1689, 1627, 1564, 1434,
5-(4-Oxothiochroman-2-yl)furan-2(5H)-one (6n). This compound
was prepared from 5n and purified by gel column chromatography
(PE/EtOAc 4/1 v/v as eluent) to give an inseparable mixture of
−1
1
377, 1226, 1195, 1147, 1073, 889, 816 cm . * = minor diastereomer.
Methyl 5-Acetoxy-4-oxo-2-(5-oxo-2,5-dihydrofuran-2-yl)-
1
chromane-2-carboxylate (6j). This compound was prepared from
diastereomers of 6n (1:1) as a brown gum (40 mg, 81%). H NMR
5
j and purified by gel column chromatography (PE/EtOAc 2/1 v/v as
(400 MHz, CDCl ): δ 8.10 (dd, 0.60H, J = 8.0 Hz, J = 1.2 Hz), 8.08*
3
eluent) to give an inseparable mixture of diastereomers of 6j (20:1) as
a colorless gum (52 mg, 75%). Anal. Calcd for C H O : C, 58.96; H,
(dd, 0.40H, J = 2.0 Hz, J = 1.6 Hz), 7.57 (dd, 0.63H, J = 5.6 Hz, J = 1.6
Hz), 7.45−7.40 (m, 1H), 7.37* (dd, 0.38H, J = 6.0 Hz, J = 1.6 Hz),
7.28−7.20 (m, 2H), 6.22 (td, 1H, J = 6.0 Hz, J = 1.6 Hz), 5.28* (dt,
0.35H, J = 5.2 Hz, J = 1.7 Hz), 5.14 (dt, 0.60H, J = 8.0 Hz, J = 1.6 Hz),
17
14
8
1
4
.08. Found: C, 58.59; H, 4.32. H NMR (400 MHz, CDCl ): δ 7.50
3
(
5
m, 2H), 6.92 (d, 1H, J = 8.4), 6.72 (d, 1H, J = 7.6), 6.35 (dd, 1H, J =
.8 Hz, J = 2.0 Hz), 5.40 (t, 1H, J = 1.7 Hz), 3.77 (s, 3H), 3.22 (d, 1H,
3.93−3.89* (m, 0.35H), 3.62−3.57 (m, 0.59H), 3.12−3.19 (m, 1H),
13
13
J = 16.6 Hz), 3.05 (d, 1H, J = 16.6 Hz), 2.36 (s, 3H). C NMR (100
MHz, CDCl ): δ 186.4, 171.1, 169.3,168.5, 159.8, 150.7, 149.8, 136.2,
3.10−2.99 (m, 1H). C NMR (100 MHz, CDCl ): δ 192.2*, 192.0,
3
171.5, 171.2*, 153.2, 152.1*, 139.2*, 138.8, 134.0, 133.9*, 130.5,
130.3*, 129.1, 129.0*, 127.6, 127.5*, 125.8, 125.6*, 123.9*, 123.3;
83.4*, 82.6, 43.1, 42.4*, 41.1, 40.7*. HRMS-ESI (m/z): calcd for
3
1
24.2, 117.2, 115.9, 113.6, 83.0, 82.6, 53.8, 41.1, 21.0. HRMS-ESI (m/
+
z): calcd for C H O [M + H] 347.0761, found 347.0769. IR
17
15
8
+
(
neat): 3419, 2920, 2846, 1749, 1684, 1653, 1558, 1522, 1457, 1200,
C H O SNa [M + Na] 269.0243, found 269.0235. IR (neat): 3343,
13
10
3
−1
1
155, 1040, 518 cm .
3091, 2923, 2375, 1786, 1756, 1679, 1589, 1460, 1437, 1288, 1264,
−1
Methyl 5-Acetoxy-7-methyl-4-oxo-2-(5-oxo-2,5-dihydrofuran-2-
1234, 1158, 1110, 1089, 1028, 884, 823, 802, 767 cm . * =
yl)chromane-2-carboxylate (6k). This compound was prepared
from 5k and purified by gel column chromatography (PE/EtOAc 2/
1
diastereomer.
Benzyl 4-Oxo-2-(5-oxo-2,5-dihydrofuran-2-yl)-3,4-dihydroquino-
line-1(2H)-carboxylate (6o). This compound was prepared from 5o
and purified by gel column chromatography (PE/EtOAc 4/1 v/v as
eluent) to give an inseparable mixture of diastereomers of 6o (1:1) as a
brown gum (55 mg, 76%). Anal. Calcd for C H NO : C, 69.41; H,
v/v as eluent) to give an inseparable mixture of diastereomers of 6k
(
6
6:1) as a colorless gum (56 mg, 78%). Anal. Calcd for C H O : C,
18
16
8
0.00; H, 4.48. Found: C, 60.37; H, 4.19. 1H NMR (400 MHz,
CDCl ): δ 7.56* (dd, 0.14H, J = 5.8 Hz, J = 1.6 Hz), 7.50 (dd, 0.86H,
J = 5.8 Hz, J = 1.6 Hz), 6.82* (d, 0.12H, J = 0.6 Hz), 6.74 (d, 0.88H, J
=
3
21 17
5
1
4.72; N, 3.85. Found: C, 69.38; H, 4.38; N, 3.67. H NMR (400 MHz,
0.6 Hz), 6.54 (d, 1H, J = 0.8 Hz), 6.33 (dd, 0.82H, J = 5.8 Hz, J = 2.0
CDCl ): δ 7.99 (d, 1H, J = 7.6 Hz), 7.71 (d, 1H, J = 8.4 Hz), 7.51 (t,
3
Hz), 6.28* (dd, 0.16H, J = 5.8 Hz, J = 2.0 Hz), 5.40* (t, 0.14H, J = 1.8
1H, J = 8.4 Hz), 7.38 (s, 5H), 7.26−7.18 (m, 2H), 6.06 (dd, 1H, J =
I
J. Org. Chem. XXXX, XXX, XXX−XXX