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9. Characterization of selected products: 3: oil; Rf 0.38
15: oil; Rf 0.60 (n-hex/ethyl acetate: 4/1); the NMR data
for 15 were collected at 200 MHz in CDCl3 at 25°C. In
order to define the structure of 15, the following experi-
(n-hex/ethyl acetate: 4/1); 1H NMR (200 MHz, CDCl3,
25°C): l 5.14 (dd, J=9.6 and 8.1 Hz, 1H, H-5), 4.37–4.18
(m, 4H, 2×OCH2CH3), 3.46 (d J=8.1 Hz, 2H, H-4),
1.40–1.22 (m, 6H, 2×OCH2CH3); MS: C9H13NO5, 216
[M+1]+.
ments were performed: H, 13C, DEPT, COSY. H NMR
(200 MHz, CDCl3, 25°C): l 7 33 (s, 5H, Ph), 5.25–5.17
(m, 6H, CH2Ph, H-5), 4.32 (q, J=7.3 Hz, 2H,
OCH2CH3), 3.44–3.30 (four lines, A part of an ABX
system, 1H, CH2O) 3.04–2.94 (four lines, B part of an
ABX system, 1H, CH2O), 2.91–2.82 (four lines, A part of
an ABX system, 1H, H-3) 2.72–2.60 (four lines, B part of
an ABX system, 1H, H-3), 1.34 (t, J=7.3 Hz, 3H,
1
1
5: oil; Rf 0.33 (n-hex/ethyl acetate: 4/1); 1H NMR (200
MHz, CDCl3, 25°C): l 7.34 (s, 5H, Ph) 5.24–5.14 (m, 6H,
CH2Ph, H-5), 4.32 (q, J=7.2 Hz, 2H, OCH2CH3), 3.46
(d, J=8.7 Hz, 2H, H-4), 1.33 (t, J=7.2 Hz, 3H,
OCH2CH3); MS: C14H15NO5, 278 [M+1]+.
8: oil; Rf 0.46 (n-hex/ethyl acetate: 4/1); 1H NMR (200
MHz, CDCl3, 25°C): l 5.36 (dd, J=9.8 and 8.2 Hz, 1H,
H-5), 4.37 (q, J=7.2 Hz, 2H, OCH2CH3), 3.59 (d, J=8.2
Hz, 2H, H-4), 1.36 (t, J=7.2 Hz, 3H, OCH2CH3); 13C
NMR (200 MHz, CDCl3, 25°C): l 158.89 (COOEt),
151.10 (CꢀN), 68.00 (C-5), 62.86 (OCH2CH3), 39.94 (C-
4), 13.99 (OCH2CH3); MS: C7H8N2O3, 169 [M+1]+.
9: oil; Rf 0.17 (n-hex/ethyl acetate: 7/3); 1H NMR (200
MHz, CDCl3, 25°C): l 5.11–4.96 (m, 1H, H-5), 4.36 (q,
J=7.2 Hz, 2H, OCH2CH3), 3.52–3.37 (four lines, A part
of an ABX system, 1H, CH2CN) 3.17–3.05 (four lines, B
part of an ABX system, 1H, CH2CN), 2.74 (d, J=5.8 Hz,
2H, H-4), 1.35 (t, J=7.2 Hz, 3H, OCH2CH3); MS:
C8H10N2O3, 183 [M+1]+.
OCH2CH3); 13C NMR:
l 169.19 (COOBn), 160.33
(COOEt), 151.42 (CꢀN), 135.28 (ipso), 128.51, 128.31,
128.17 (Ph), 79.25 (C-5), 66.68 (CH2Ph), 61.97
(OCH2CH3), 39.37 (C-4), 38.65 (CH2COOBn), 13.96
(OCH2CH3); MS: C15H17NO5, 292 [M+1]+.
1
18: oil; Rf 0.17 (n-hex/ethyl acetate: 1/1); H NMR (200
MHz, CDCl3, 25°C): l 7.29 (s, 5H, Ph) 6.91 (bb, 1H,
NH), 6.58 (bb, 1H, NH), 5.08 (t, J=8.5 Hz, 1H, H-5),
4.49 (d, J=6.0 Hz, 2H, CH2CH(CH3)2), 3.58 (s, 2H,
CH2Ph), 3.20–3.02 (m, 2H, H-4), 1.83–1.69 (m, 1H,
CH2CH(CH3)2), 0.90 (s, 3H, CH2CH(CH3)2), 0.86 (s, 3H,
CH2CH(CH3)2); MS: C16H21N3O3, 304 [M+1]+.
10. In some cases the formation of furoxane 4 could not be
prevented, thus yields were lower. Nevertheless, as furox-
ane remained preferentially in the ionic liquid, the prod-
ucts could be isolated pure without chromatography.
11. The rate acceleration of the cycloaddition of imidates
derived from diethylmalonate and electron rich aromatic
aldehydes in ionic liquid has been reported: Dubreuil, J.
F.; Buzureau, J. P. Tetrahedron Lett. 2000, 41, 7351.
1
12: oil; Rf 0.40 (n-hex/ethyl acetate: 4/1); H NMR (200
MHz, CDCl3, 25°C): l 6.68 (d, J=7.3 Hz, 1H, H-5), 4.25
(q, J=7.0 Hz, 2H, OCH2CH3), 3.43–3.30 (four lines, A
part of an ABX system, 1H, H-4) 3.15–3.05 (four lines, B
part of an ABX system, 1H, H-4), 1.96 (s, 3H, OCH3),
1.26 (t, J=7.0 Hz, 3H, OCH2CH3); MS: C8H11NO5, 202
[M+1]+.