S. Kanemasa et al. / Tetrahedron 56 (2000) 1057–1064
1063
1.9 Hz, Ar), 8.65 (1H, dd, J4.8 and 1.7 Hz, Ar), and 8.80
(1H, d, J2.2 Hz, Ar); 13C NMR (CDCl3) d 42.53 (C-4),
82.94 (C-5), 123.63, 125.71, 125.82, 128.43, 128.85,
133.71, 140.41, 147.84, 151.09 (Ph and Ar) and 153.77
(C-3); MS m/z (rel. intensity, %) 224 (Mϩ, 67), 153 (80),
136 (52), 107 (72), 89 (69), and 77 (base peak). Anal.
Found: C, 75.05; H, 5.42; N, 12.44. Calcd for C14H12N2O:
C, 74.98; H, 5.39; N, 12.49.
peak), and 77 (21). Anal. Found: C, 75.91; H, 7.98; N, 7.45.
Calcd for C12H15NO: C, 76.16; H, 7.99; N. 7.40.
3-(t-Butyl)-5-phenyl-2-isoxazoline (4j). Light yellow oil;
IR (neat) 2990, 1610, 1360, 1250, 890, 760, and
1
700 cmϪ1; H NMR (CDCl3) d 1.22 (9H, s, t-Bu), 2.92
(1H, dd, Jgem16.7 Hz and J4–58.1 Hz, one of H-4), 3.39
(1H, dd, Jgem16.7 Hz and J4–510.6 Hz, the other of H-4),
5.52 (1H, dd, J5–48.1 and 10.6 Hz, H-5), and 7.25–7.37
(5H, m, Ph); 13C NMR (CDCl3) d 28.05, 32.97 (each t-Bu),
42.59 (C-4), 81.61 (C-5), 125.62, 127.87, 128.57, 141.40
(each Ph), and 165.39 (C-3); MS m/z (rel. intensity, %)
203 (Mϩ, 94), 188 (21), 170 (11), 131 (24), 104 (base
peak), 97 (52), and 77 (23). Anal. Found: C, 76.45; H,
8.44; N, 6.81. Calcd for C13H17NO: C, 76.81; H, 8.43; N,
6.89.
5-Phenyl-3-(4-pyridyl)-2-isoxazoline (4f). Colorless plates
from CH2Cl2–hexane; mp 67–69ЊC; IR (KBr) 3000, 2200,
1
1590, 1400, 1350, 900, 810, 720, and 690 cmϪ1; H NMR
(CDCl3) d 3.32 (1H, dd, Jgem16.7 Hz and J4–58.5 Hz,
one of H-4), 3.76 (1H, dd, Jgem16.7 Hz and J4–5
11.1 Hz, the other of H-4), 5.81 (1H, dd, J5–411.1 and
8.5 Hz, H-5), 7.32–7.42 (5H, m, Ph), 7.54 (2H, dd, J4.5
and 1.7 Hz, Ar), and 8.68 (2H, dd, J4.5 and 1.7 Hz, Ar);
13C NMR (CDCl3) d 42.11 (C-4), 83.46 (C-5), 120.88,
125.81, 128.52, 128.88, 136.77, 140.19, 150.46 (Ph and
Ar), and 154.59 (C-3); MS m/z (rel. intensity, %) 224
(Mϩ, 58) and 104 (base peak). Anal. Found: C, 74.98; H,
5.42; N, 12.44. Calcd for C14H12N2O: C, 74.98; H, 5.39; N,
12.49.
3-Benzoyl-5-phenyl-2-isoxazoline (4k). Light yellow oil;
1H NMR (CDCl3) d 3.39 (1H, dd, Jgem17.6 Hz and J4–5
8.7 Hz, one of H-4), 3.78 (1H, dd, Jgem17.6 Hz and J4–5
11.4 Hz, the other of H-4), 5.77 (1H, dd, J5–48.7 and
11.4 Hz, H-5), 7.33–7.42 (5H, m, Ph), 7.48 (2H, m, Ar),
7.61 (1H, m, Ar), and 8.24 (2H, m, Ar); 13C NMR (CDCl3) d
41.82 (C-4), 84.21 (C-5), 125.90, 128.40, 128.61, 128.87,
130.33, 133.63, 135.75, 139.66 (each Ph), 157.37 (C-3), and
186.20 (CO); MS m/z (rel. intensity, %) 252 (Mϩϩ1, 65)
and 105 (base peak). Anal. Found: C, 76.25; H, 5.28; N,
5.73. Calcd for C16H13NO2: C, 76.48; H, 5.21; N, 5.57.
3-Benzyl-5-phenyl-2-isoxazoline (4g). Colorless oil; IR
(neat) 3040, 2920, 1610, 1500, 1460, 1430, 1080, 1040,
1
760, and 700 cmϪ1; H NMR (CDCl3) d 2.75 (1H, dd,
Jgem17.1 Hz and J4–58.4 Hz, one of H-4), 3.18 (1H, dd,
Jgem17.1 Hz and J4–510.9 Hz, the other of H-4), 3.64
(1H, d, Jgem14.8 Hz, one of PhCH2), 3.71 (1H, d,
Jgem14.8 Hz, the other of PhCH2), 5.47 (1H, dd, J5–4
8.4 and 10.9 Hz, H-5), and 7.20–7.30 (10H, m, Ph); 13C
NMR (CDCl3) d 33.91 (PhCH2), 44.27 (C-4), 81.61 (C-5),
125.56, 126.92, 127.82, 128.44, 128.64, 135.47, 140.84
(each Ph), and 157.23 (C-3); MS m/z (rel. intensity, %)
238 (Mϩϩ1, base peak), 107 (6), 91 (16), and 77 (4).
Anal. Found: C, 80.67; H, 6.41; N, 5.85. Calcd for
C16H15NO: C, 80.98; H, 6.37; N, 5.90.
Reaction of 2-furancarbaldehyde oxime (6) with BTMA
ICl4
To a stirred solution of 2-furancarbaldehyde oxime (5,
111 mg, 1 mmol) in dichloromethane (5 ml, 0.2 M), was
added BTMA ICl4 (419 mg, 1 mmol). After stirring for
5 min at room temperature, the reaction mixture was diluted
with diethyl ether (25 ml) and the precipitate was filtered
off. The filtrate was evaporated in vacuo, and then the dark
red residue was chromatographed on silica gel with hexane–
diethyl ether (1:1 v/v) to give 5-chloro-2-furancarbaldehyde
oxime (6, 121 mg, 83%) as a colorless solid. The chlori-
nation and cycloaddition with methyl acrylate were
performed according to Method A to give 5-chloro-2-furan-
carbohydroximoyl chloride (7) in 60% yield and methyl
3-(5-chloro-2-furyl)-2-isoxazoline-5-carboxylate (8) in 80%
yield.
5-Phenyl-3-propyl-2-isoxazoline (4h). Light yellow oil; 1H
NMR (CDCl3) d 0.97 (3H, t, J7.5 Hz, CH3 of n-Pr), 1.62
(2H, tt, J7.5 and 7.5 Hz, CH2 of n-Pr), 2.36 (2H, t,
J7.5 Hz, CH2 of n-Pr), 2.89 (1H, dd, Jgem16.9 Hz and
J4–58.2 Hz, one of H-4), 3.35 (1H, dd, Jgem16.9 Hz and
J4–510.9 Hz, the other of H-4), 5.54 (1H, dd, J5–410.9
and 8.2 Hz, H-5), 7.29–7.38 (5H, m, Ph); 13C NMR (CDCl3)
d 13.71, 19.76, 29.57 (each n-Pr), 45.30 (C-4), 81.16 (C-5),
125.67, 127.94, 128.63, 141.37 (each Ph), and 158.34 (C-3);
MS m/z (rel. intensity, %) 189 (Mϩ, 55), 161 (21), 117 (18),
104 (base peak), 91 (17), and 77 (20). Anal. Found: C,
75.89; H, 8.00; N, 7.39. Calcd for C12H15NO: C, 76.16; H,
7.99; N, 7.40.
5-Chloro-2-furancarbaldehyde oxime (6). Colorless plates
from Et2O–hexane; mp 110–111ЊC; IR (KBr) 3200, 1630,
1
1590, 1200, 1010, 970, 930, 840, and 800 cmϪ1; H NMR
(400 MHz, CDCl3) d 6.33 (1H, d, J3.5 Hz, Furyl), 7.29
(1H, d, J3.5 Hz, Furyl), 7.42 (1H, s, CHyN), and 8.80
(1H, br. s, NOH); 13C NMR (400 MHz, CDCl3) d 109.11,
120.36, 136.28, 138.40 (each Ar), and 144.72 (CHyNOH);
MS m/z (rel. intensity, %) 137 (11), 121 (7), 81 (31), and 69
(base peak). Anal. Found: C, 42.29; H, 3.06; N, 9.87. Calcd
for C5H4NO2Cl: C, 41.26; H, 2.77; N, 9.62.
5-Phenyl-3-isopropyl-2-isoxazoline (4i). Light yellow oil;
1H NMR (CDCl3) d 1.18 (3H, d, J7.0 Hz, one of Me), 1.19
(3H, d, J7.0 Hz, the other of Me), 2.75 (1H, sep,
J7.0 Hz, Me2CH), 2.94 (1H, dd, Jgem16.9 Hz and J4–5
8.2 Hz, one of H-4), 3.63 (1H, dd, Jgem16.9 Hz and J4–5
10.9 Hz, the other of H-4), 5.53 (1H, dd, J5–410.9 and
8.2 Hz, H-5), and 7.27–7.38 (5H, m, Ph); 13C NMR (CDCl3)
d 20.08, 20.09, 27.89 (each i-Pr), 43.24 (C-4), 81.24 (C-5),
125.67, 127.93, 128.62, 141.39 (each Ph), and 162.98 (C-3);
MS m/z (rel. intensity, %) 189 (Mϩ, 58), 117 (18), 104 (base
5-Chloro-2-furancarbohydroximoyl chloride (7). Light
1
yellow solid; H NMR (400 MHz, CDCl3) d 6.29 (1H, d,
J3.4 Hz, Furyl), and 6.85 (1H, d, J3.4 Hz, Furyl), and
8.98 (1H, br. s, NOH).