Calcd for C11H14NO3 (MH+): 196.0974, Found: 196.0975. MS
CH3), 2.97 [dA(ABX), 1 H, JAB = 20.8, JAX = 7.2 Hz, CH2(Ha)],
(ESI) m/z 196 (M + H)+, 178, 150, 132.
3.17-3.43 (m, 3 H), 4.06-4.15 [m, 2 H, CH2(Et)], 5.31 [br.s, 1
3
H, CH(OH)], 7.25-7.56 (m, 5 H, HAr), 7.79 (d, 2 H, JHH
=
Ethyl 2-phenyl-3-hydroxy-3-(4-nitrophenyl)propanoate 12a
(Procedure C). [50 mg, 77% yield from aldehyde (32 mg)].
Rf 0.29 (Cyclohexane/AcOEt = 80:20). Light brown oil. First
diastereomer: 1H NMR (400 MHz, CDCl3) d 1.11 (t, 3 H, J =
7.2 Hz, CH3), 3.20 (bs, 1 H, OH), 3.81 (d, H, J = 6.0 Hz,
CHPh), 4.02-4.13 (m, 2 H, CH2), 5.42 (d, 1 H, J = 6.0 Hz,
CHOH), 7.19-7.22 (m, 2 H, HAr), 7.28-7.41 (m, 3 H, HAr), 7.41
(d, 2 H, J = 8.8 Hz, HAr), 8.12 (d, 2 H, J = 8.8 Hz, HAr). 13C
NMR (100 MHz, CDCl3) d 13.9 (CH3), 58.8 (CPh), 61.4 (CH2),
8.4 Hz, HAr), 8.12 (d, 2 H, JHH = 8.4 Hz, HAr),. 13C NMR
(100 MHz, CDCl3) d 14.0 (CH3), 34.7 (CH2), 47.8 (CH), 61.4
[CH2(Et)], 72.6 (CH), 123.7, 126.9, 128.0, 128.6, 133.5, 136.3,
3
=
=
147.4, 148.6, 173.2 (C O), 198.1 (C O). IR (neat) 3475 (O-H),
-1
=
=
1725 (C O), 1683 (C O), 1517, 1343 cm . HRMS (ESI):
Calcd. for C19H19NO6 (MH+): 358.1291. Found: 358.1293.
Ethyl 2-phenyl-2-methyl-3-hydroxy-3-(4-nitrophenyl) propa-
noate 12d (Procedure E or Procedure C). Purification on
silica-gel column chromatography (cyclohexane/Et2O = 90:10).
[54 mg, 39% yield from 3a (100 mg). Two diastereoisomers.
73.8 (COH), 123.3, 127.5, 128.2, 128.7, 129.2, 133.4, 147.5, 148.0
1
=
(CAr), 172.6 (C O). Second diastereomer: H NMR (400 MHz,
1
CDCl3) d 1.22 (t, 3 H, J = 6.8 Hz, CH3), 3.49 (d, 1 H, J =
4.0 Hz, OH), 3.78 (d, 1 H, J = 9.2 Hz, CHPh), 4.14-4.27 (m,
2 H, CH2), 5.27 (dd, 1 H, J = 9.2 Hz, J = 4.0 Hz, CHOH),
7.02-7.05 (m, 2 H, HAr), 7.20-7.23 (m, 5 H, HAr), 8.03 (d, 2 H,
J = 8.4 Hz, HAr). 13C NMR (100 MHz, CDCl3) d 14.0 (CH3),
59.9 (CPh), 61.6 (CH2), 75.7 (COH), 123.2, 127.5, 128.0, 128.4,
Colorless oil. First diastereomer: H NMR (400 MHz, CDCl3)
d 1.13 (t, 3 H, 3JHH = 7.2 Hz, CH3), 1.44 (s, 3 H, CH3), 3.70 (d,
3
1 H, JHH = 2.6 Hz, OH), 4.14 (ABX3, 2 H, CH2O), 5.30 [d, 1
3
H, JHH = 2.6 Hz, CH(OH)], 6.80-7.23 (m, 7 H, HAr), 7.97 (d,
2 H, 3JHH = 8.8 Hz, HAr). 13C NMR (400 MHz, CDCl3) d 13.9
(CH3), 19.2 (CH3), 55.5 (CH), 61.7 (ArCH), 77.9, 122.4, 127.8,
=
=
128.8, 134.5, 147.4, 148.0 (CAr), 173.1 (C O). IR (neat) 3526 (O-
128.0, 129.2, 137.0, 146.2, 147.4 (CAr), 176.5 (C O). Second
-1
H), 2984, 1705 (C O), 1517, 1345 cm . HRMS (ESI): Calcd.
diastereomer: 1H NMR (400 MHz, CDCl3) d 1.13 (t, 3 H, 3JHH
=
=
for C18H20NO5 (MH+): 330.1341. Found: 330.1330.
7.2 Hz, CH3), 1.42 (s, 3 H, CH3), 3.91 (d, 1 H, JHH = 3.0 Hz,
3
3
OH), 4.14 (ABX3, 2 H, CH2O), 5.43 [d, 1 H, JHH = 3.0 Hz,
Ethyl
2-(phenylmethyl)-3-hydroxy-3-(4-nitrophenyl)pro-
CH(OH)], 6.78-7.23 (m, 7 H, HAr), 7.83 (d, 2 H, 3JHH = 8.8 Hz,
HAr). 13C NMR (400 MHz, CDCl3) d 14.1 (CH3), 19.2 (CH3),
56.3 (CH), 61.8 (ArCH), 77.9, 122.1, 126.6, 127.9 (CHar), 128.4,
panoate 12b (Procedure A). [147 mg, 68% yield from 3a
(100 mg)]. Rf 0.28 (Cyclohexane/AcOEt = 80:20). Colorless
oil. First diastereomer: 1H NMR (400 MHz, CDCl3)·d 0.94 (t, 3
=
128.7, 139.0, 145.9, 147.1 (CAr), 177.1 (C O). HRMS (ESI)
Calcd for C18H20NO5 (MH+): 330.1341, Found: 313.1330.
3
H, JHH = 6.8 Hz, CH3), 2.81-2.86 (m, 1 H, CHBn), 2.97-3.02
(m, 2 H, CH2Ph), 3.44 (br.s, 1 H, OH), 3.89-3.96 [m, 2 H,
3
CH2(Et)], 5.16 [d, 1 H, JHH = 3.8 Hz, CH(OH)], 7.04 (d, 2
2-(N-acetylamino)-2-carboethoxy-3-(phenylmethyl)propionic
acid 11e48. [1.7 g, 89% yield from malonate (2 g)]. White solid
3
H, JHH = 8.7 Hz, HAr), 7.13-7.25 (m, 3 H, HAr), 7.58 (d, 2 H,
◦
3JHH = 8.7 Hz, HAr), 8.20 (d, 2 H, 3JHH = 8.7 Hz, HAr). 13C NMR
(100 MHz, CDCl3) d 13.8 (CH3), 32.8 (CH2Ph), 54.4 (CHBn),
60.9 [CH2(Et)], 72.9 (CHOH), 123.6, 126.5, 127.1, 128.4, 128.8,
(mp 135 C). H NMR (CDCl3) d 1.24 [t, 3 H, J = 7.2 Hz,
CH3(Et)], 1.92 [s, 3 H, CH3], 3.39 [dA(AB), 1 H, JAB = 13.6 Hz,
CH2], 3.45 [dB(AB), 1 H, JAB = 13.6 Hz, CH2], 4.12 [q, 2 H,
J = 7.2 Hz, CH2(Et)], 6.99-7.29 (m, 5 H, HAr), 13.74 (bs, 1
H, CO2H). 13C NMR (CDCl3) d 13.8, 22.2, 37.3, 61.3, 66.8,
126.7, 128.1, 129.8, 135.6, 167.5, 168.3, 169.2. IR (neat) 3324
(O-H), 1721 (C O), 1598, 1525, 1201 cm . HRMS (ESI) Calcd
for C14H17NO5 (MH+): 280.1172, Found: 280.1185.
1
=
138.3, 147.5, 148.6 (CAr), 174.2 (C O). IR (neat) 3481 (O-H);
-1
1
=
1722 (C O); 1603; 1519; 1344 cm . Second diastereomer: H
NMR (400 MHz, CDCl3) d 0.90 (t, 3 H, 3JHH = 7.2 Hz, CH3),
3
-1
=
2.84-3.00 (m, 3 H, CHBn), 3.68 (d, 1 H, JHH = 8.0 Hz, OH),
3
3.82-3.95 [m, 2 H, CH2(Et)], 4.79 [dd, 1 H, JHH = 8.0 Hz,
3JHH = 4.3 Hz, CH(OH)], 7.11-7.24 (m, 5 H, HAr), 7.41 (d, 2
Ethyl 2-(N-acetylamino) -2-(phenylmethyl) -3-hydroxy-3-(4-
nitrophenyl) propanoate 12e (Procedure C). [144 mg, 77% yield
from 11e (134 mg)]. First diastereomer: Light brown solid (mp
125 ◦C). Rf 0.25 (Cyclohexane/AcOEt = 70:30). 1H NMR
(400 MHz, CDCl3) d 1.21 [t, 3 H, J = 7.2 Hz, CH3(Et)], 1.98
(s, 3 H, COCH3), 3.05-3.10 (m, 2 H, CH2Ph), 4.05-4.21 [m, 2
H, CH2(Et)], 5.60 (s, 1 H, CHOH), 5.85 (bs, 1 H, OH), 5.99
(s, 1 H, NH), 7.02 (m, 2 H, HAr), 7.26 (m, 2 H, HAr), 7.48
(d, 2 H, J = 6.8 Hz, HAr), 8.19 (d, 2 H, J = 6.8 Hz, HAr),
8.26-8.33 (m, 1 H, HAr). 13C NMR (100 MHz, CDCl3) d 13.9
[CH3(Et)], 24.1 (COCH3), 37.6 (CH2Ph), 62.8 [CH2(Et)], 70.7,
77.0 (COH), 123.3, 127.6, 128.1, 128.8, 129.7, 131.3, 134.7,
H, JHH = 8.5 Hz, HAr), 8.11 (d, 2 H, JHH = 8.5 Hz, HAr). 13C
NMR (100 MHz, CDCl3) d 13.9 (CH3), 35.8 (CH2Ph), 53.9
(CHBn), 61.0 [CH2(Et)], 72.9 (CHOH), 123.6, 126.8, 126.9,
3
3
=
128.6, 129.0, 137.7, 147.4, 149.7 (CAr), 174.2 (C O). IR (neat)
3531 (O-H), 1732 (C O), 1604, 1516, 1351 cm . HRMS (ESI):
Calcd. for C18H20NO5 (MH+): 330.1341. Found: 330.1330.
-1
=
Ethyl
2-[hydroxy(4-nitrophenyl)methyl]-4-oxo-4-phenyl-
butanoate 12c (Procedure A). [55 mg, 77% yield from 3b
(50 mg)]. Rf 0.2 (Cyclohexane/AcOEt = 70:30). Colorless oil.
1
Major diastereomer: H NMR (400 MHz, CDCl3) d 1.06 (t, 3
H, 3JHH = 7.2 Hz, CH3), 3.20-3.43 (m, 3 H), 3.77 (d, 1 H, 3JHH
=
=
=
6.2 Hz, OH), 3.98-4.06 [m, 2 H, CH2(Et)], 5.09 [t, 1 H, 3JHH
147.4, 170.4, 172.3 (C O). IR (neat) 3260 (OH), 1728, 1645
(C O), 1510, 1345 cm . HRMS (ESI) Calcd for C20H23N2O6
=
6.2 Hz, CH(OH)], 7.25-7.56 (m, 5 H, HAr), 7.84 (d, 2 H, 3JHH
-1
=
8.4 Hz, HAr), 8.12 (d, 2 H, JHH = 8.4 Hz, HAr),. 13C NMR
(100 MHz, CDCl3) d 14.0 (CH3), 37.4 (CH2), 47.3 (CH), 61.4
[CH2(Et)], 73.0 (CH), 123.6, 127.0, 128.1, 128.7, 133.7, 136.2,
(MH+): 387.1556, found: 378.1567. Second diastereomer: Light
brown solid (mp 123 ◦C). Rf 0.1 (Cyclohexane/AcOEt = 70:30).
1H NMR (400 MHz, CDCl3) d 1.43 [t, 3 H, J = 7.2 Hz,
CH3(Et)], 1.98 (s, 3 H, COCH3), 3.46 [d, 1 H, J = 14.0 Hz,
CH2Ph (Ha)], 4.07 [d, 1 H, J = 14.0 Hz, CH2Ph (Hb)], 4.23-4.32
3
=
=
147.5, 149.0, 173.6 (C O), 197.4 (C O). Minor diastereomer:
1H NMR (400 MHz, CDCl3) d 1.12 (t, 3 H, JHH = 7.2 Hz,
3
258 | Green Chem., 2010, 12, 252–259
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The Royal Society of Chemistry 2010
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