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L. Tian et al.
PAPER
were concentrated in vacuo to afford crude 1-hydroxyprop-2-ene-3-
sulfonic acid. The crude 1-hydroxyprop-2-ene-3-sulfonic acid was
heated at 130–145 °C in an oil bath and then distilled in vacuo to
give 1 (12 g); bp 118 °C/14 Pa; mp 83–84 °C.
J = –11.19 Hz, 1 H, H-6), 4.46 (dd, J = 3.54, –11.19 Hz, 1 H, H-6),
4.17 (t, J = 6.82, 6.25 Hz, 1 H H-3a).
13C NMR (200 MHz, CDCl3): = 162.30, 131.61, 130.51, 129.23,
128.11, 124.71, 117.23 (arom), 79.84 (C-6a), 72.01 (C-3), 70.21 (C-
6), 69.24 (C-3a).
Cycloaddition of Phenylnitrones 2a-j with Sultone 1; General
Procedure
Anal. Calcd for C16H14FNO4S: C, 57.31; H, 4.21; N, 4.18. Found:
C, 57.03; H, 3.98; N, 4.27
A toluene or benzene solution of nitrone 2 (1 mmol) and the sultone
1 (0.12 g, 1 mmol) was heated at 60 °C (for phenylnitrones) or 40
°C (for cyclic nitrones) for the time indicated in Table 1. During the
reaction, additional amounts of nitrones (ca. 0.2 mmol) were added
twice. Evaporation of the solvent and separation of the resulting
brown residue by column chromatography gave the crude product,
which was recrystallized from suitable solvents.
3-(2,4-Dichlorophenyl)-2-phenyl-6a,3a-dihydro-5,4-oxathiain-
4,4-dioxide[3,4-d]isoxazolidine (3e)
Recrystallized from EtOAc–petroleum ether (1:4); white crystals;
mp 155–156 °C.
1H NMR (200 MHz, CDCl3): = 6.9–7.5 (m, 8 Harom), 5.55 (d, J =
3.33 Hz, 1 H, H-3) 5.36 (dd, J = 6.24, 3.35 Hz, 1 H, H-6a), 4.66 (d,
J = –11.15 Hz, 1 H, H-6), 4.52 (dd, J = –11.15, 3.35 Hz, 1 H, H-6),
4.21 (dd, J = 6.24, 3.33 Hz, 1 H, H-3a).
13C NMR (200 MHz, CDCl3): = 146.34, 135.32, 134.11, 132.74,
130.08, 128.92, 127.80, 124.14, 117.04 (arom), 79.63 (C-6a), 70.09
(C-3), 69.24 (C-6), 67.29 (C-3a).
2,3-Diphenyl-6a,3a-dihydro-5,4-oxathiain-4,4-dioxide[3,4-d]-
isoxazolidine (3a)
Recrystallized from EtOAc–petroleum ether (1:3); white crystals;
mp 147–148 °C.
1H NMR (200 MHz, CDCl3): = 7.25–7.45 (m, 5 Harom), 6.8–7.2
(m, 5 Harom), 5.42 (dd, J = 3.21, 6.68 Hz, 1 H, H-6a), 4.79 (d, J =
6.32 Hz, 1 H, H-3), 4.64 (d, J = –11.07 Hz, 1 H, H-6), 4.48 (dd, J =
3.21, –11.07 Hz, 1 H, H-6), 4.22 (t, J = 6.68, 6.32 Hz, 1 H, H-3a).
Anal. Calcd for C16H13NO4Cl2S: C, 49.76; H, 3.39; N, 3.63. Found:
C, 49.8; H, 3.405; N, 3.54.
13C NMR (200 MHz, CDCl3): = 146.7, 131.64, 129.77, 128.65,
128.03, 119.2 (arom), 79.26 (C-6a), 71.21 (C-3), 70.32 (C-6), 69.32
(C-3a).
3-(3-Nitrophenyl)-2-phenyl-6a,3a-dihydro-5,4-oxathiain-4,4-
dioxide[3,4-d]isoxazolidine (3f)
Recrystallized from toluene; white crystals; mp 143–144 °C.
1H NMR (200 MHz,CDCl3): = 6.9–8.4 (m, 9 Harom), 5.47 (dd, J =
3.13, 6.66 Hz, 1 H, H-6a), 4.94 (d, J = 6.19 Hz, 1 H, H-3), 4.62 (d,
J = –11.12 Hz, 1 H, H-6), 4.51 (dd, J = 3.13, –11.12 Hz, 1 H, H-6),
4.16 (t, J = 6.66, 6.19 Hz, 1 H, H-3a).
13C NMR (200 MHz, CDCl3): = 148.76, 145.71, 138.00, 134.04,
130.37, 128.98, 125.84, 124.05, 122.53, 119.65 (arom), 79.35 (C-
6a), 71.42 (C-3), 70.01 (C-6), 69.92 (C-3a).
Anal. Calcd for C16H15NO4S: C, 60.55; H, 4.76; N, 4.41. Found: C,
60.51; H, 5.01; N, 4.64.
3-(4-Chlorophenyl)-2-phenyl-6a,3a-dihydro-5,4-oxathiain-4,4-
dioxide[3,4-d]isoxazolidine (3b)
Recrystallized from EtOAc–petroleum ether (1:3); white crystals,
mp 164–165 °C.
1H NMR (200 MHz, CDCl3): = 6.9–7.4 (m, 9 Harom), 5.43 (dd, J =
3.52, 6.55 Hz, 1 H, H-6a), 4.77 (d, J = 5.9 Hz, 1 H, H-3), 4.6 (d, J =
–11.033 Hz, 1 H, H-6), 4.52 (dd, J = 3.52 Hz, –11.033 Hz, 1 H, H-
6), 4.13 (t, J = 6.55, 5.9 Hz, 1 H, H-3a).
13C NMR (200 MHz, CDCl3): = 146.3, 137.02, 131.34, 129.69,
128.65, 127.13, 119.2 (arom), 79.34 (C-6a), 72.01 (C-3), 70.72 (C-
6), 69.33 (C-3a).
Anal. Calcd for C16H14N2O6S: C, 55.48; H, 4.07; N, 8.09. Found: C,
55.53; H, 3.92; N, 7.99
3-(3-Methylphenyl)-2-phenyl-6a,3a-dihydro-5,4-oxathiain-4,4-
dioxide[3,4-d]isoxazolidine (3g)
Recrystallized from EtOAc–petroleum ether (1:4); white crystals,
mp 114–115 °C.
1H NMR (200 MHz, CDCl3): = 6.9–7.3 (m, 9 Harom), 5.37 (dd, J =
3.26, 6.66 Hz, 1 H, H-6a), 4.7 (d, J = 6.24 Hz, 1 H, H-3), 4.59 (d,
J = –11.08 Hz, 1 H, H-6), 4.45 (dd, J = 3.26, –11.08 Hz, 1 H, H-6),
4.16 (t, J = 6.66, 6.24 Hz, 1 H, H-3a).
13C NMR (200 MHz, CDCl3): = 146.88, 139.16, 136.12, 129.80,
129.19, 128.68, 128.19, 124.88, 124.69, 119.04 (arom), 79.26 (C-
6a), 72.49 (C-3), 70.81 (C-6), 69.41 (C-3a).
Anal. Calcd for C16H14ClNO4S: C, 54.62; H, 4.02; N, 3.98. Found:
C, 54.51; H, 3.96; N, 4.05.
3-(4-Methylphenyl)-2-phenyl-6a,3a-dihydro-5,4-oxathiain-4,4-
dioxide[3,4-d]isoxazolidine (3c)
Recrystallized from EtOAc–petroleum ether (1:3); white crystals;
mp 123–124 °C.
1H NMR (200 MHz, CDCl3): = 6.96–7.4 (m, 9 Harom), 5.39 (dd, J
= 3.33, 6.57 Hz, 1 H, H-6a), 4.77 (d, J = 6.27 Hz, 1 H, H-3), 4.59
(d, J = –11.06 Hz, 1 H, H-6), 4.45 (dd, J 3.33, –11.06 Hz, 1 H, H-
6), 4.17 (t, J = 6.57, 6.27 Hz, 1 H, H-3a), 2.34 (s, 3 H, CH3).
13C NMR (200 MHz, CDCl3): = 146.74, 138.90, 132.96, 129.99,
128.66, 127.58, 124.98, 119.22 (arom), 79.16 (C-6a), 72.41 (C-3),
70.71 (C-6), 69.46 (C-3a).
Anal. Calcd for C17H17NO4S: C, 61.62; H, 5.17; N, 4.23. Found: C,
61.585; H, 5.2; N, 4.3
2-(4-Chlorophenyl)-3-phenyl-6a,3a-dihydro-5,4-oxathiain-4,4-
dioxide[3,4-d]isoxazolidine (3h)
Recrystallized from EtOAc–petroleum ether (1:3); white crystals,
mp 166–167 °C.
1H NMR (200 MHz, CDCl3): = 6.7–7.4 (m, 9 Harom), 5.31 (dd, J =
3.65, 6.68 Hz, 1 H, H-6a), 4.66 (d, J = 6.17 Hz, 1 H, H-3), 4.52 (d,
J = –11.05 Hz, 1 H, H-6), 4.43 (dd, J = 3.65, –11.05 Hz, 1 H, H-6),
4.10 (t, J = 6.68, 6.17 Hz, 1 H, H-3a).
13C NMR (200 MHz, CDCl3): = 144.61, 131.65, 129.77, 129.21,
128.03, 125.34, 119.32 (arom); 79.26 (C-6a), 72.22 (C-3), 70.12 (C-
6), 69.67 (C-3a).
Anal. Calcd for C17H17NO4S: C, 61.62; H, 5.17; N, 4.23. Found: C,
61.48; H, 5.18; N, 4.37.
3-(4-Fluorophenyl)-2-phenyl-6a,3a-dihydro-5,4-oxathiain-4,4-
dioxide[3,4-d]-isoxazolidine (3d)
Recrystallized from EtOAc–petroleum ether (1:3); white crystals,
mp 182–183 °C.
1H NMR (200 MHz, CDCl3): = 6.9-7.5 (m, 9 Harom), 5.38 (dd, J =
3.54, 6.82 Hz, 1 H, H-6a), 4.76 (d, J = 6.25 Hz, 1 H, H-3), 4.59 (d,
Anal. Calcd for C16H14ClNO4S: C, 54.62; H, 4.02; N, 3.98. Found:
C, 54.62; H, 3.93; N, 3.87.
Synthesis 2003, No. 9, 1329–1334 ISSN 1234-567-89 © Thieme Stuttgart · New York