SELEZNEVA et al.
1668
saturated solution of NH4Cl was added, methanol was
evaporated, the residue was diluted with 2 mL of H2O,
the reaction product was extracted with CH2Cl2, the
extract was dried with MgSO4. After concentrating the
solution and purification of the residue by column
chromatography on SiO2 (eluent petroleum ether-ethyl
acetate, 1 : 1→1 : 2) yield 0.08 g (62%). Light-yellow
oily substance. IR spectrum, ν, cm–1: 1738, 1718,
1090. Mixture of rotamers in a ratio 5 : 3.
(С=СH2), 128.85 (СHarom), 130.24 (СHarom), 133.02
(СHarom), 133.20 (С=СH2), 137.64 (Сarom), 149.14
(Carom), 166.76 (CO2), 171.66 (CO2). Found, %: С
43.21; Н 4.27; N 7.36; S 8.14. С14Н16N2O9S.
Calculated, %: С 43.3; Н 4.15; N 7.21; S 8.26.
Methyl iminoacetate (10). To solution of 0.09 g
(0.51 mmol) of amine 2а in 5 mL of anhydrous THF at
–78°С was added 1.28 mL (1.28 mmol) of 1 M
solution of LiN(SiMe3)2. The reaction mixture was
stirred at –20°С for 2 h, warmed to room temperature
and 5% solution of HCl was added till pH 5, THF was
distilled off, the reaction product was extracted with
ethyl acetate, combined organic layers were washed
with saturated solution of NaCl, dried with MgSO4,
evaporated, the residue was chromatographed on a
column with SiO2 (eluent petroleum ether-ethyl
acetate, 7 : 3→1 : 1). Yield 0.01 g (22%). Light-yellow
oily substance. 1Н NMR spectrum, δ, ppm: 3.87 s (3H,
OMe), 5.87 s (1H, CH=), 6.71 br.s (1H, NH). 13С
NMR spectrum, δ, ppm: 52.14 (OMe), 137.61 (=СH),
164.86 (CO2).
1
Major diastereomer. Н NMR spectrum, δ, ppm:
1.20 d (3Н, СН3, J 7.1 Hz), 2.17 s (3Н, СН3), 2.76 m
(1H, Н2), 3.39 d.d (1H, Н3А, 2J 15.1, 3J 5.9 Hz), 3.70 m
(1H, Н3А), 3.68 s (3H, OMe), 3.70 s (3H, OMe), 3.97 d
2
2
(1H, Н2′A, J 17.2 Hz), 4.12 d (1H, Н2′В, J 17.2 Hz).
13С NMR spectrum, δ, ppm: 15.33 (СН3), 21.08 (СН3),
39.28 (С2), 47.71 (С3), 52.07 (OMe), 52.41 (С2′),
169.77 (CO2), 171.42 (NC=O), 175.00 (CO2).
1
Minor diastereomer. Н NMR spectrum, δ, ppm:
11.14 d (3Н, СН3, J 7.2 Hz), 1.75 m (1H, H2), 2.00 s
2
(3Н, СН3), 2.91 m (1H, Н3A), 3.21 d.d (1H, Н3B, J
15.1, 3J 5.9 Hz), 3.65 s (3H, OMe), 3.75 s (3H, OMe),
2
2
4.05 d (1H, Н2'A, J 18.6 Hz), 4.17 d (1H, Н2'B, J
18.6 Hz). 13С NMR spectrum, δ, ppm: 15.52 (СН3),
21.53 (СН3), 38.73 (С2), 51.04 (С3), 51.99 (С2ʹ), 52.37
(ОMе), 169.25 (CO2), 171.49 (NC=O), 175.00 (CO2).
Found, %: С 51.79; Н 7.59; N 6.19. С10Н17NO5.
Calculated, %: С 51.94; Н 7.41; N 6.06.
Methyl 1-acetyl-4-methyl-3-oxopyrrolidin-2-
carboxylate (11). To a solution of 0.12 g (0.52 mmol)
of diester 2b in 5 mL of anhydrous THF at –78°С in an
argon atmosphere was added 0.60 mL (0.60 mmol) of
1 M solution of LiN(SiMe3)2. The reaction mixture
was stirred at –40°С for 1 h, then temperature of the
mixture was raised to room temperature and the
mixture was stirred for 3 h. Into the reaction mixture
5 mL of saturated solution of NH4Cl was added, THF
was distilled off, the reaction product was extracted
with CH2Cl2, the extract was dried with MgSO4,
evaporated, the residue was purified by column
chromatography on a column with SiO2 (eluent
petroleum ether–ethyl acetate, 1 : 2). Yield 0.032 g
(31%). Light-yellow oily substance. IR spectrum, ν,
cm–1: 1745, 1735.
Methyl 2-{hydroxy[(2-methoxy-2-oxoethyl)-(2-
nitrobenzene-1-sulfonyl)amino]methyl}prop-2-
enoate (8). To a solution of 0.1 g (0.36 mmol) of N-
nosyl derivative 5 and 0.08 g (0.45 mmol) of methyl 2-
(bromomethyl)acrylate in 5 mL of CH2Cl2 at 0°С was
added 2 mL of 50% solution of NaOH and a catalytic
amount of Bu4NI. The reaction mixture was stirred at
0°С for 4 h (TLC monitoring). The reaction product
was extracted with CH2Cl2, combined organic layers
were washed with H2O, saturated solution of NaCl,
dried with MgSO4. After concentrating the solution the
residue was chromatographed on a column with SiO2
(eluent petroleum ether–ethyl acetate, 3 : 1→2 : 1).
Yield 0.06 g (44%). Light-yellow oily substance. IR
1
Major isomer. Н NMR spectrum, δ, ppm: 1.23 d
(3Н, СН3, J 7.1 Hz), 2.18 s (3Н, СН3), 2.85 d.d.q (1H,
2
3
Н4, J 7.1, 9.8, 10.1 Hz), 3.56 t (1H, Н5А, J 10.1, J
10.1 Hz), 3.80 s (3H, OMe), 3.83 s (1H, Н2), 4.24 t
(1H, Н5В, J 10.1, J 9.8 Hz). 13С NMR spectrum, δ,
ppm: 12.37 (СН3), 21.09 (СН3), 45.65 (С5), 51.13 (С4),
53.19 (OMe), 64.83 (С2), 166.21 (CO2), 166.97
(NC=O), 205.76 (C=O).
2
3
1
spectrum, ν, cm–1: 3410, 1725, 1675, 1330, 1060. Н
NMR spectrum, δ, ppm: 2.50 br.s (OH), 3.40 d (1H,
CН2, 2J 14.9 Hz), 3.45 d (1H, CН2, 2J 14.9 Hz), 3.68 s
(3H, OMe), 3.75 s (3H, OMe), 5.00 s (1H, CHOH),
5.70 s (1H, =CH2), 6.25 s (1H, =CH2), 7.45 m (1H,
1
Minor isomer. Н NMR spectrum, δ, ppm: 1.25 d
H
arom), 7.60 m (1Нarom), 7.90 d (1Нarom, J 8.2 Hz). 13С
(3Н, СН3, J 7.2 Hz), 2.16 s (3Н, СН3), 2.94 d.d.q (1H,
2
3
NMR spectrum, δ, ppm: 48.62 (СH2), 51.89 (OMe),
52.69 (OMe), 60.52 (CHOH), 124.96 (СHarom), 126.73
Н4, J 7.7, 9.8, 7.2 Hz), 3.42 d.d (1H, Н5А, J 10.0, J
7.5 Hz), 3.77 s (3H, OMe), 4.24 t (1H, Н5В, 2J 10.0, 3J
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 54 No. 11 2018