2270
M.R. da Silva et al. / Tetrahedron 70 (2014) 2264e2271
(75.5 MHz, CDCl3)
d
(ppm): 15.6 (CH3), 21.0 (CH2), 25.1 (CH3), 32.5
150.3 (C), 170.3 (C), and 172.1 (C). HRMS [ESIþ, m/z] calcd for
C
(CH2), 40.0 (CH2), 54.9 (CH), 67.8 (CH2), 125.6 (2CH), 132.2 (2CH),
12H14N2O5[Naþ] 289.0800, found 289.0767.
145.9 (C), 149.2 (C), 171.7 (C), and 173.2 (C). HRMS [ESIþ, m/z] calcd
20
for C15H20N2O5[Naþ] 331.1270, found 331.1295. [
a
]
þ93.1 (c 1.0,
4.4.20. Spectroscopical data of butyl 2-acetylamino-3-(2-
nitrophenyl)propanoate (10g). Solid. Rf (50% EtOAc/hexane): 0.34.
Mp: 94e96 ꢁC. IR (NaCl) v 3263, 3059, 1752, 1657, 1522, and
D
CHCl3) for 98% ee (S).
4.4.15. Spectroscopical data of allyl 2-acetylamino-3-(4-nitrophenyl)
1203 cmꢂ1 1H NMR (300.13 MHz, CDCl3)
. d (ppm): 0.90 (t, 3H,
propanoate (11e). Solid. Rf (EtOAc/Hexane:MeOH 4:5:1): 0.78. Mp:
J¼7.4 Hz), 1.23e1.34 (m, 2H), 1.51e1.58 (m, 2H), 1.92 (s, 3H), 3.31
(dd, 1H, J¼13.6 and 8.1 Hz), 3.49 (dd, 1H, J¼13.8 and 6.1 Hz),
4.01e4.16 (m, 2H), 4.91 (apparent dt, 1H, J¼8.1 and 6.1 Hz), 6.32 (br
d, 1H, J¼7.6 Hz), 7.41 (m, 2H), 7.55 (dd, 1H, J¼7.7 and 1.3 Hz), and
92e94 ꢁC. IR (NaCl): v 3280, 1761, 1650, 1529, and 1355 cmꢂ1 1H
.
NMR (300.13 MHz, CDCl3)
d
(ppm): 2.01 (s, 3H), 3.19 (dd, 1H, J¼13.7
and 5.7 Hz), 3.31 (dd, 1H, J¼13.8 and 6.3 Hz), 4.62 (d, 2H, J¼5.8 Hz),
4.94 (m, 1H), 5.27e5.35 (m, 2H), 5.80e5.93 (m, 1H), 6.04 (br d, 1H,
J¼7.2 Hz), 7.30 (d, 2H, J¼8.5 Hz), and 8.14 (d, 2H, J¼8.5 Hz). 13C NMR
7.92 (d, 1H, J¼8.4 Hz). 13C NMR (75.5 MHz, CDCl3)
d (ppm): 14.0
(CH3), 19.4 (CH2), 23.3 (CH3), 30.8 (CH2), 35.2 (CH2), 53.4 (CH), 66.1
(CH2), 125.2 (CH), 128.6 (CH), 132.0 (C), 133.1 (CH), 133.4 (CH), 149.8
(C), 170.2 (C), and 171.8 (C). HRMS [ESIþ, m/z] calcd for
(75.5 MHz, CDCl3)
d (ppm): 23.3 (CH3), 38.0 (CH2), 53.1 (CH), 66.6
(CH2), 119.9 (CH2), 123.9 (2CH), 130.4 (2CH), 131.2 (2CH), 144.0 (C),
147.4 (C), 169.9 (C), and 171.0 (C). HRMS [ESIþ, m/z] calcd for
C
15H20N2O5[Naþ] 331.1270, found 331.1269.
20
C
14H16N2O5[Naþ] 315.0957, found 315.0955. [
a
]
ꢂ37.0 (c 0.7,
D
CHCl3) for 90% ee (R).
4.4.21. Spectroscopical data of allyl 2-acetylamino-3-(2-nitrophenyl)
propanoate (11g). Oil. Rf (50% EtOAc/hexane): 0.71. IR (NaCl): v
3250,1749,1660,1556, and 1341 cmꢂ1. 1H NMR (300.13 MHz, CDCl3)
4.4.16. Spectroscopical data of methyl 2-acetylamino-3-(3-
nitrophenyl)propanoate (9f). Oil. Rf (50% EtOAc/hexane): 0.47. IR
d
(ppm): 1.95 (s, 3H), 3.35 (dd, 1H, J¼13.6 and 8.1 Hz), 3.55 (dd, 1H,
(NaCl): v 3280, 1744, 1658, 1530, and 1352 cmꢂ1
.
1H NMR
J¼13.8 and 6.1 Hz), 4.55e4.68 (m, 2H), 4.91 (apparent dt, 1H, J¼8.1
and 6.1 Hz), 5.24e5.32 (m, 2H), 5.79e5.93 (m, 1H), 6.23 (br d, 1H,
J¼7.9 Hz), 7.42 (m, 2H), 7.55 (m, 1H), and 7.92 (dd, 1H, J¼8.4 and
(300.13 MHz, CDCl3)
d
(ppm): 2.00 (s, 3H), 3.17 (dd, 1H, J¼13.7 and
5.8 Hz), 3.31 (dd, 1H, J¼13.9 and 5.7 Hz), 3.76 (s, 3H), 4.92 (m, 1H),
6.23 (br d, 1H, J¼6.8 Hz), 7.48 (d, 2H, J¼5.2 Hz), 7.98 (s, 1H), and 8.11
1.7 Hz). 13C NMR (75.5 MHz, CDCl3)
d (ppm): 22.9 (CH3), 37.2 (CH2),
(m, 1H). 13C NMR (75.5 MHz, CDCl3)
d
(ppm): 25.0 (CH3), 39.6 (CH2),
53.3 (CH), 68.0 (CH2), 116.6 (CH2), 125.2 (CH),128.6 (CH), 129.4 (CH),
132.0 (C), 133.1 (CH), 133.4 (CH), 150.4 (C), 166.3 (C), and 170.1 (C).
HRMS [ESIþ, m/z] calcd for C14H16N2O5[Naþ] 315.0957, found
315.0949.
54.6 (CH3), 55.0 (CH), 124.2 (CH), 126.2 (CH), 131.5 (CH), 137.4 (CH),
140.2 (C), 150.2 (C), 171.9 (C), and 173.6 (C). HRMS [ESIþ, m/z] calcd
20
for C12H14N2O5[Naþ] 289.0800, found 289.0803. [
CH2Cl2) for 60% ee (R).
a]
ꢂ90.6 (c 1.0,
D
4.4.22. Spectroscopical data of methyl 2-acetylamino-3-(naphthalen-
2-yl)propanoate (9h). Solid. Rf (50% EtOAc/hexane): 0.35.
Mp¼93e95 ꢁC. IR (NaCl) v 3277, 3056, 1745, 1655, 1544, and
4.4.17. Spectroscopical data of butyl 2-acetylamino-3-(3-
nitrophenyl)propanoate (10f). Solid. Rf (50% EtOAc/hexane): 0.38.
Mp: 103e105 ꢁC. IR (NaCl) v 3280, 3071, 1740, 1659, 1531, and
1219 cmꢂ1. 1H NMR (300.13 MHz, CDCl3)
d (ppm): 1.95 (s, 3H), 3.22
1211 cmꢂ1
.
1H NMR (300.13 MHz, CDCl3)
d
(ppm): 0.88 (t, 3H,
(dd, 1H, J¼20.2 and 6.3 Hz), 3.30 (dd, 1H, J¼19.9 and 6.0 Hz), 3.71 (s,
3H), 4.97 (apparent dt, 1H, J¼6.9 and 6.0 Hz), 6.37 (br d, 1H,
J¼7.7 Hz), 7.24 (dd, 1H, J¼8.0 and 1.6 Hz), 7.42e7.49 (m, 2H), 7.58 (s,
J¼7.6 Hz), 1.23e1.35 (m, 2H), 1.52e1.61 (m, 2H), 1.96 (s, 3H), 3.13
(dd, 1H, J¼13.9 and 6.1 Hz), 3.26 (dd, 1H, J¼13.7 and 6.0 Hz), 4.09 (t,
2H, J¼6.6 Hz), 4.83e4.89 (m,1H), 6.47 (br d,1H, J¼7.2 Hz), 7.41e7.49
(m, 2H), 7.97 (s, 1H), and 8.06 (d, 1H, J¼7.4 Hz). 13C NMR (75.5 MHz,
1H), and 7.77 (d, 3H, J¼3.4 Hz). 13C NMR (75.5 MHz, CDCl3)
d (ppm):
23.3 (CH3), 38.3 (CH2), 52.7 (CH3), 53.7 (CH), 126.2e133.9 (10CAr),
CDCl3)
d
(ppm): 15.6 (CH3), 21.0 (CH2), 24.9 (CH3), 32.4 (CH2), 39.6
170.4 (C), and 172.6 (C). HRMS [ESIþ, m/z] calcd for C16H17NO3[Naþ]
20
(CH2), 55.1 (CH), 67.7 (CH2), 124.1 (CH), 126.2 (CH), 131.4 (CH), 137.5
294.1106, found 294.1068. [
a
]
D
ꢂ28.2 (c 1.0, CHCl3) for 27% ee of
(CH), 140.4 (C), 150.2 (C), 172.0 (C), and 173.3 (C). HRMS [ESIþ, m/z]
the (R)-enantiomer. Lit [
a]
20 þ91.5 (c 1.0, CHCl3) for 86% ee for the
D
calcd for C15H20N2O5[Naþ] 331.1270, found 331.1267. [
0.9, CHCl3) for 87% ee (S).
a]
20 þ51.9 (c
(S)-enantiomer.15 Lit [
(R)-enantiomer.18
a
]
20 ꢂ104.7 (c 0.99, CHCl3) for>99% ee for the
D
D
4.4.18. Spectroscopical data of allyl 2-acetylamino-3-(3-nitrophenyl)
propanoate (11f). Oil. Rf (60% EtOAc/hexane): 0.34. IR (NaCl): v
3277, 1743, 1659, 1531, and 1352 cmꢂ1. 1H NMR (300.13 MHz, CDCl3)
4.4.23. Spectroscopical data of butyl 2-acetylamino-3-(naphthalen-
2-yl)propanoate (10h). Solid. Rf (50% EtOAc/hexane): 0.43. Mp:
148e150 ꢁC. IR (NaCl) v 3280, 3056, 1739, 1659, 1545, and
d
(ppm): 1.99 (s, 3H), 3.17 (dd, 1H, J¼13.9 and 6.0 Hz), 3.30 (dd, 1H,
1202 cmꢂ1 1H NMR (300.13 MHz, CDCl3)
. d (ppm): 0.86 (t, 3H,
J¼13.9 and 5.9 Hz), 4.62 (m, 2H), 4.92 (m, 1H), 5.25e5.34 (m, 2H),
5.87 (m, 1H), 6.33 (br d, 1H, J¼7.4 Hz), 7.43e7.51 (m, 2H), 7.98 (d, 1H,
J¼7.2 Hz), 1.21e1.31 (m, 2H), 1.50e1.59 (m, 2H), 1.97 (s, 3H),
3.21e3.33 (m, 2H) 4.10 (t, 2H, J¼6.6 Hz), 4.97 (apparent dt, 1H, J¼7.1
and 6.0 Hz), 6.23 (br d, 1H, J¼7.7 Hz), 7.26 (dd, 1H, J¼8.3 and 1.9 Hz),
7.46 (m, 2H), 7.57 (s, 1H), and 7.73e7.86 (m, 3H). 13C NMR
J¼2.0 Hz), and 8.08 (m, 1H). 13C NMR (75.5 MHz, CDCl3)
d (ppm):
23.3 (CH3), 37.9 (CH2), 53.4 (CH), 68.7 (CH2), 120.0 (CH2), 122.5 (CH),
124.6 (CH), 129.7 (CH), 131.3 (CH), 135.9 (CH), 138.5 (C), 148.5 (C),
170.2 (C), and 171.2 (C). HRMS [ESIþ, m/z] calcd for C14H16N2O5[Naþ]
(75.5 MHz, CDCl3)
d (ppm): 13.6 (CH3), 19.0 (CH2), 23.1 (CH3), 30.5
(CH2), 38.2 (CH2), 53.3 (CH), 65.4 (CH2), 125.3e133.6 (10CAr), 169.8
315.0957, found 315.0954. [
a
]
20 ꢂ67.9 (c 0.8, CHCl3) for 81% ee (R).
(C), and 171.9 (C). HRMS [ESIþ, m/z] calcd for C19H23NO3[Naþ]
D
336.1576, found 336.1544. [
a
]
20 þ90.2 (c 0.5, CHCl3) for 92% ee (S).
D
4.4.19. Spectroscopical data of methyl 2-acetylamino-3-(2-
nitrophenyl)propanoate (9g). Oil. Rf (60% EtOAc/hexane): 0.23. IR
4.4.24. Spectroscopical data of allyl 2-acetylamino-3-(naphthalen-2-
(NaCl):
v
3278, 1740, 1659, 1541, and 1339 cmꢂ1
.
1H NMR
yl)propanoate (11h). Oil. Rf (50% EtOAc/hexane): 0.42. IR (NaCl): v
(300.13 MHz, CDCl3)
d
(ppm): 1.94 (s, 3H), 3.33 (dd, 1H, J¼13.9 and
1739, 1699, 1510, and 1374 cmꢂ1 1H NMR (300.13 MHz, CDCl3)
.
8.0 Hz), 3.52 (dd, 1H, J¼13.9 and 6.0 Hz), 3.72 (s, 3H), 4.92 (dt, 1H,
J¼7.9 and 5.8 Hz), 6.32 (br d, 1H, J¼7.7 Hz), 7.39e7.45 (m, 2H), 7.57
d
(ppm): 1.99 (s, 3H), 3.24e3.37 (m, 2H), 4.63 (d, 2H, J¼6.0 Hz), 5.01
(apparent dt, 1H, J¼13.0 and 5.8 Hz), 5.22e5.34 (m, 2H), 5.80e5.93
(m, 1H), 6.09 (br d, 1H, J¼7.5 Hz), 7.26 (dd, 1H, J¼9.0 and 1.6 Hz),
7.48 (m, 2H), 7.58 (s, 1H), and 7.74e7.82 (m, 3H). 13C NMR (75 MHz,
(dt, 1H, J¼7.8 and 1.4 Hz), and 7.92 (dd, 1H, J¼7.9 and 1.4 Hz). 13
C
NMR (75.5 MHz, CDCl3)
d (ppm): 23.3 (CH3), 35.0 (CH2), 53.0 (CH),
53.3 (CH3), 125.3 (CH), 128.6 (CH), 131.9 (C), 133.1 (CH), 133.5 (CH),
CDCl3) d (ppm): 23.3 (CH3), 38.2 (CH2), 53.5 (CH), 66.4 (CH2), 119.5