I
Synthesis
X. Yan et al.
Paper
1
Methyl 4-(4-Methoxyphenyl)-7,7-dimethyl-5-oxo-2-(trifluoro-
H NMR (500 MHz, CDCl ): δ = 1.00 (s, 3 H), 1.13 (s, 3 H), 2.17–2.28
3
methyl)-5,6,7,8-tetrahydro-4H-chromene-3-carboxylate (5c)
(m, 2 H), 2.52 (s, 2 H), 3.63 (s, 3 H), 3.89 (s, 3 H), 4.80 (s, 1 H), 7.32 (d,
J = 8.3 Hz, 2 H), 7.97 (d, J = 8.3 Hz, 2 H).
Yellow solid; yield: 176 mg (43%); mp 89.8–92.6 °C.
1
3
C NMR (125 MHz, CDCl ): δ = 27.2, 29.1, 32.2, 37.4, 40.4, 50.6, 52.1,
IR (KBr): 2959, 1734, 1672, 1462, 1377, 1295, 1209, 1149, 1077, 730
3
1
–1
52.7, 112.4, 116.5, 118.8 (q, J = 272.5 Hz), 128.3, 129.4, 130.0, 139.6
cm
.
C,F
2
(q, J = 38.3 Hz), 146.1, 162.6, 164.6, 166.7, 195.7.
1
C,F
H NMR (500 MHz, CDCl ): δ = 1.01 (s, 3 H), 1.12 (s, 3 H), 2.17–2.27
3
19
F NMR (470 MHz, CDCl ): δ = –67.2 (s, CF ).
(m, 2 H), 2.50 (s, 2 H), 3.64 (s, 3 H), 3.76 (s, 3 H), 4.68 (s, 1 H), 6.81 (d,
3
3
MS (ESI): m/z = 439 [(M + H)]+.
J = 8.8 Hz, 2 H), 7.15 (d, J = 8.8 Hz, 2 H).
1
3
+
C NMR (125 MHz, CDCl ): δ = 27.3, 29.1, 32.2, 36.5, 40.4, 50.7, 52.6,
HRMS (DART): m/z [(M + H)] calcd for C22H21F O : 439.1363; found:
439.1352.
3
3
6
1
5
5.1, 113.0, 114.0, 117.4, 118.9 (q, J = 272.3 Hz), 129.3, 133.4, 138.7
C,F
2
(q, J = 38.0 Hz), 158.9, 162.1, 165.0, 195.9.
C,F
1
9
F NMR (470 MHz, CDCl ): δ = –67.3 (s, CF ).
Methyl 7,7-Dimethyl-5-oxo-4-(m-tolyl)-2-(trifluoromethyl)-
5,6,7,8-tetrahydro-4H-chromene-3-carboxylate (5j)
3
3
MS (ESI): m/z = 411.1 [(M + H)]+.
+
Yellow solid; yield: 177 mg (45%); mp 77.9–80.4 °C.
HRMS (DART): m/z [(M + H)] calcd for C21H21F O : 411.1414; found:
3
5
411.1407.
IR (KBr): 2959, 1741, 1670, 1646, 1372, 1293, 1207, 1146, 1074, 1046,
–1
996 cm .
1
Methyl 7,7-Dimethyl-4-(4-nitrophenyl)-5-oxo-2-(trifluorometh-
H NMR (500 MHz, CDCl ): δ = 1.02 (s, 3 H), 1.11 (s, 3 H), 2.18–2.27
3
yl)-5,6,7,8-tetrahydro-4H-chromene-3-carboxylate (5d)
(m, 2 H), 2.30 (s, 3 H), 2.51 (s, 2 H), 3.62 (s, 3 H), 4.70 (s, 1 H), 7.00–
7
.02 (m, 3 H), 7.15–7.18 (m, 1 H).
White solid; yield: 200 mg (47%); mp 96.8–99.6 °C.
13
C NMR (125 MHz, CDCl ): δ = 21.4, 27.3, 29.0, 32.2, 37.3, 40.3, 50.6,
IR (KBr): 2953, 1734, 1636, 1520, 1375, 1348, 1206, 1169, 1086, 1042,
3
1
–
1
52.5, 112.8, 117.4, 118.9 (q, JC,F = 272.4 Hz), 125.1, 128.0, 128.5,
7
24 cm .
2
128.9, 129.9, 138.2, 138.7 (q, J = 37.8 Hz), 162.3, 164.9, 195.9.
1
C,F
H NMR (500 MHz, CDCl ): δ = 1.00 (s, 3 H), 1.14 (s, 3 H), 2.18–2.30
3
19
F NMR (470 MHz, CDCl ): δ = –67.2 (s, CF ).
(m, 2 H), 2.54 (s, 2 H), 3.65 (s, 3 H), 4.86 (s, 1 H), 7.44 (d, J = 8.5 Hz, 2
3
3
MS (ESI): m/z = 395 [(M + H)]+.
H), 8.17 (d, J = 8.5 Hz, 2 H).
1
3
+
C NMR (125 MHz, CDCl ): δ = 27.3, 29.0, 32.2, 37.3, 40.4, 50.5, 52.9,
HRMS (DART): m/z [(M + H)] calcd for C21H21F O : 395.1465; found:
395.1462.
3
3
4
1
1
12.0, 115.7, 118.7 (q, JC,F = 272.8 Hz), 123.9, 129.3, 140.3 (q,
JC,F = 38.5 Hz), 147.3, 148.3, 163.0, 164.3, 195.8.
2
19
F NMR (470 MHz, CDCl ): δ = –67.1 (s, CF ).
Methyl 7,7-Dimethyl-4-(3-nitrophenyl)-5-oxo-2-(trifluorometh-
3
3
MS (ESI): m/z = 426 [(M + H)]+.
+
yl)-5,6,7,8-tetrahydro-4H-chromene-3-carboxylate (5k)
White solid; yield: 170 mg (40%); mp 107.2–108.4 °C.
HRMS (DART): m/z [(M + H)] calcd for C20H18F NO : 426.1159; found:
3
6
426.1151.
IR (KBr): 2966, 1743, 1643, 1531, 1377, 1208, 1172, 1150, 1078, 1046,
–1
731 cm .
1
Methyl 4-(4-Chlorophenyl)-7,7-dimethyl-5-oxo-2-(trifluorometh-
H NMR (500 MHz, CDCl ): δ = 1.02 (s, 3 H), 1.14 (s, 3 H), 2.18–2.30
3
yl)-5,6,7,8-tetrahydro-4H-chromene-3-carboxylate (5e)
(m, 2 H), 2.56 (s, 2 H), 3.65 (s, 3 H), 4.87 (s, 1 H), 7.47–7.50 (m, 1 H),
7
.60–7.62 (m, 1 H), 8.09–8.11 (m, 2 H).
Pale yellow solid; yield: 161 mg (39%); mp 101.3–102.4 °C.
13
C NMR (125 MHz, CDCl ): δ = 27.3, 29.1, 32.3, 37.2, 40.4, 50.5, 52.9,
IR (KBr): 2969, 1731, 1670, 1639, 1373, 1208, 1165, 1078, 1044, 719
3
1
–1
112.0, 115.8, 118.7 (q, JC,F = 272.6 Hz), 122.8, 123.1, 129.6, 134.5,
cm
.
2
140.2 (q, J = 38.3 Hz), 143.3, 148.5, 163.1, 164.4, 195.8.
1
C,F
H NMR (500 MHz, CDCl ): δ = 1.00 (s, 3 H), 1.12 (s, 3 H), 2.17–2.28
3
19
F NMR (470 MHz, CDCl ): δ = –67.1 (s, CF ).
(m, 2 H), 2.51 (s, 2 H), 3.65 (s, 3 H), 4.72 (s, 1 H), 7.18 (d, J = 8.5 Hz, 2
3
3
MS (ESI): m/z = 426 [(M + H)]+.
H), 7.26 (d, J = 8.5 Hz, 2 H).
1
3
+
C NMR (125 MHz, CDCl ): δ = 27.3, 29.1, 32.2, 36.8, 40.4, 50.6, 52.7,
HRMS (DART): m/z [(M + H)] calcd for C20H18F NO : 426.1159; found:
426.1155.
3
3
6
1
1
12.6, 116.7, 118.8 (q, JC,F = 272.4 Hz), 128.9, 129.6, 133.4, 139.4 (q,
JC,F = 38.1 Hz), 139.7, 162.4, 164.7, 195.8.
2
19
F NMR (470 MHz, CDCl ): δ = –67.2 (s, CF ).
Methyl 4-(3-Chlorophenyl)-7,7-dimethyl-5-oxo-2-(trifluorometh-
3
3
MS (ESI): m/z = 415 [(M + H)]+.
yl)-5,6,7,8-tetrahydro-4H-chromene-3-carboxylate (5m)
HRMS (DART): m/z [(M + H)]+ calcd for C20H18ClF O : 415.0918;
Pale yellow solid; yield: 277 mg (67%); mp 77.1–78.6 °C.
3
4
found: 415.0913.
IR (KBr): 2961, 1736, 1668, 1640, 1436, 1374, 1309, 1205, 1172, 1077,
–1
1044, 793 cm .
1
Methyl 4-[4-(Methoxycarbonyl)phenyl]-7,7-dimethyl-5-oxo-2-
H NMR (500 MHz, CDCl ): δ = 1.01 (s, 3 H), 1.11 (s, 3 H), 2.18–2.27
3
(
trifluoromethyl)-5,6,7,8-tetrahydro-4H-chromene-3-carboxylate
(m, 2 H), 2.47–2.55 (m, 2 H), 3.64 (s, 3 H), 4.72 (s, 1 H), 7.11–7.13 (m,
1 H), 7.17–7.23 (m, 3 H).
(5h)
1
3
White solid; yield: 166 mg (38%); mp 126.5–128.2 °C.
C NMR (125 MHz, CDCl ): δ = 27.3, 29.0, 32.2, 37.1, 40.3, 50.6, 52.7,
3
1
1
12.3, 116.6, 118.8 (q, JC,F = 272.7 Hz), 126.4, 127.9, 128.3, 129.9,
IR (KBr): 2961, 1724, 1671, 1639, 1374, 1285, 1202, 1167, 1077, 1048,
2
–1
134.5, 139.5 (q, J = 38.1 Hz), 143.1, 162.6, 164.6, 195.7.
740 cm
.
C,F
19
F NMR (470 MHz, CDCl ): δ = –67.2 (s, CF ).
3
3
©
Georg Thieme Verlag Stuttgart · New York — Synthesis 2016, 48, A–J