Molecules 2017, 22, 119
8 of 14
(E)-4-Methoxyethyl-3-phenylbut-2-enoate (2b) [49]. Following GP-1, 2.00 g (13.4 mmol) of 4-methoxy
acetophenone (1b) and 6.86 g (34.6 mmol, 2.6 eq) of triethylphosphono acetate and 1.33 g (33.4 mmol,
2
.5 eq) of sodium hydride in 40 mL THF were reacted. The product was purified by column
1
chromatography (CH/Et O = 9:1, R = 0.24) and isolated as yellow oil: 2.3 g, 10.4 mmol, 77%. H-NMR
2
f
(300 MHz, CDCl3):
δ (ppm) = 1.31 (t, 3H, J = 7.2 Hz, CH3CH ), 2.56 (d, 3H, J = 1.2 Hz, CH ), 3.82 (s,
2 3
3
H, CH O), 4.20 (q, 2H, J = 7.2 Hz, CH CH2), 6.11 (d, 1H, J = 1.2 Hz, C=CH), 6.89 (m, 2H, Har.), 7.45
3
3
13
(
(
m, 2H, Har.). C-NMR (75 MHz, CDCl3):
CH3 H ), 113.8 (Car.), 115.3 ( H=C), 127.6 (Car.), 134.3 (Car.), 154.8 (CH=
(cm ) = 2979 (s), 2914 (m), 1709 (s), 1625 (w), 1603 (m), 1513 (s), 1344 (s), 1157 (m), 1082
δ (ppm) = 14.3 (CH CH ), 17.6 (CH ), 55.3 (CH O), 59.6
3 2 3 3
C
C
C), 160.4 (Car.), 167.0 (C=O).
2
−
1
IR (Film):
ν
+
+
+
(
m). MS (EI, 70 eV): m/z (%) = 221 (M , 15), 192 (M
−
CH CH , 12), 175 (M
−
OCH CH , 100), 148
2 3
2
3
+
(M
−
O=COH CH , 83). CHN-analysis: (C H O , M = 220.11 g/mol)—calcd.: 70.89% C 7.32% H,
2 3 13 16 3
found: 71.04% C 7.63% H.
E)-3-(4-Methoxyphenyl)but-2-ene-1-ol (3b) [50]. Following GP-2, 2.00 g (10.5 mmol) of ester 2b was
reduced with 21 mL DIBAL-H (21 mmol, 2 eq, 1 M solution in hexane) in 60 mL of diethylether.
The product 3b was purified by column chromatography (PE/Et O 9:1, R = 0.10) and isolated as
(
2
f
1
colorless oil: 1.79 g, 10.1 mmol, 96%. H-NMR (300 MHz, CDCl ):
δ (ppm) = 2.06 (s, 3H, CH ), 3.81 (s,
3
3
3
7
H, CH O), 4.35 (d, 2H, J = 6.9 Hz, CH ), 5.92 (dt, 1H, J = 1.2 Hz, 6.9 Hz, C=CH), 6.87 (m, 2H, Har.),
3 2
13
.36 (m, 2H, Har.). C-NMR (75 MHz, CDCl3):
δ (ppm) = 16.0 (CH ), 55.3 (CH O), 59.9 (CH OH),
3 3 2
1
13.6 (Car.), 124.8 (C=CH), 126.8 (Car.), 135.3 (CH =C), 137.3 (Car.), 158.9 (Car.).
2
(
E)-3-(4-Methoxyphenyl)but-2-enal (4b) [51]. Following GP-3, 1.79 g (10.1 mmol) of the alcohol 4a and
1
8 g of MnO in 250 mL of toluene were reacted. The product was purified by column chromatography
2
1
(PE/Et O = 1:1, R = 0.28) and isolated as colorless oil: 1.79 g (6.9 mmol, 68%). H-NMR (300 MHz,
2
f
CDCl3):
δ
(ppm) = 2.54 (s, 3H, CH ), 3.84 (s, 3H, CH O), 6.38 (dd, 1H, J = 1.2 Hz, 7.8 Hz, C=CH), 6.93
3
3
13
(d, 2H, J = 9 Hz, Har.), 7.53 (d, 2H, J = 9 Hz, Har.), 10.15 (d, 1H, J = 7.8 Hz, CHO). C-NMR (75 MHz,
CDCl3):
δ
(ppm) = 16.0 (CH ), 55.4 (CH O), 114.0 (Car.), 125.5 (C=
C
H), 127.8 (Car.), 132.4 (Car.), 156.9
3
3
−
1
(C=CH), 161.3 (Car.), 191.2 (CHO). IR (film):
ν (cm ) = 2957 (w), 2837 (m), 1649 (s), 1593 (s), 1506 (m),
8
24 (s).
(
E)-Ethyl-3-hydroxy-5-(4-methoxyphenyl)hex-4-enoate (5b). Following GP-4, 325 mg (1.8 mmol) of the
aldehyde 4b and 0.13 mL (1.25 mmol) of ethyl acetate were reacted. The product 5a was purified by
column chromatography (PE/Et O 1:1, R = 0.18) and isolated as yellow oil: 360 mg, 1.4 mmol, 77%.
2
f
1
H-NMR (300 MHz, CDCl3):
δ (ppm) = 1.28 (t, 3H, J = 7.2 Hz, CH3CH O), 2.08 (s, 3H, CH ), 2.60 (m,
2 3
2
H, CH ), 2.95 (br s, 1H, OH), 3.80 (s, 3H, CH O), 4.18 (q, 2H, J = 7.2 Hz, CH CH2O), 4.96 (m, 1H,
2
3
3
CHO), 5.72 (dd, 1H, J = 0.9 Hz, 8.4 Hz, C=CH), 6.85 (d, 2H, J = 8.7 Hz, Har.), 7.33 (m, 2H, J = 8.7 Hz,
13
H
ar.). C-NMR (75 MHz, CDCl3):
δ
(ppm) = 14.1 (
C
H CH ), 16.3 (CH ), 41.6 (CH ), 55.2 (CH O),
3
2
3
2
3
6
0.7 (CH3
ar.), 172.3 (C=O). IR (Film):
C
H ), 65.8 (CHOH), 113.6 (Car.), 126.7 (C=
C
H), 126.9 (Car.), 135.1 (Car.), 137.3 (
C
=CH), 159.0
2
−
1
(C
ν
(cm ) = 3429(s), 2982 (s), 2831(m), 1731 (m), 1606 (m), 1506 (s), 826 (s).
+
+
+
MS (EI, 70 eV): m/z (%) = 264 (M , 21), 249 (M
35 (CH O(C H )CHCH , 100), 115 (39).
−
CH , 12), 246 (M
−
H O, 27), 177 (90), 159 (76),
2
3
1
3
6
4
3
(
E)-5-(4-Methoxyphenyl)hex-4-ene-1,3-diol (6b). Following GP-5, 175 mg (0.66 mmol) of the aldol 6a was
reduced with 63 mg (1.65 mmol, 2.5 eq) of NaBH and 51 mg (0.22 mmol, 0.3 eq) of I . The product
4
2
was purified by column chromatography (CHCl /MeOH 9:1, R = 0.27) and isolated as colorless solid:
3
f
1
1
40 mg, 0.63 mmol, 96%. H-NMR (300 MHz, CDCl ):
δ
(ppm) = 1.79 (m, 2H, CH ), 2.04 (s, 3H, CH ),
3
2
3
3
.34 (br s, 2H, 2
×
OH), 3.78 (s, 3H, OCH ), 3.84 (m, 2H, CH2OH), 4.77 (m, 1H, C
H
OH), 5.75 (dd, 1H,
3
1
3
J = 1.2 Hz, 8.4 Hz, C=CH), 6.83 (d, 2H, J = 8.7 Hz, Har.), 7.32 (d, 2H, J = 8.7 Hz, Har.). C-NMR (75 MHz,
CDCl3):
δ
(ppm) = 16.0 (CH ), 38.8 (CH ), 55.1 (OCH ), 60.7 (CH OH), 68.4 (CHOH), 113.5 (C=
C
H),
3
2
3
2
−
1
1
1
1
26.7 (Car.), 128.5 (Car.), 135.1 (Car.), 135.9 (C=CH), 158.8 (Car.). IR (Film): ν (cm ) = 3332 (s), 2938 (s),
605 (m), 1510 (s), 1245 (s), 1032 (s), 826 (m). MS (EI, 70 eV): m/z (%) = 222 (M , 12), 204 (M
1), 177 (C H O , 45), 159 (49), 135 (100), 115 (39).
+
+
−
H O,
2
+
11
13
2