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I. Ferna´ndez, L. Mun˜oz / Tetrahedron: Asymmetry 17 (2006) 2548–2557
with 5% HCl (2·) and then 10% NaHSO3 (2·). The organic
solution was dried over anhydrous Na2SO4, filtered and
concentrated under reduced pressure. The crude product
was purified by column chromatography.
MS (FAB+): m/e (relative intensity, %) 348 (M++1, 45),
307 (15), 289 (18), 252 (11), 242 (12), 241 (12), 240 (14),
239 (15), 228 (14), 228 (15), 227 (12), 226 (13), 221 (16),
219 (11), 215 (13), 203 (11), 202 (16), 192 (11), 191 (14),
190 (11), 189 (14), 181 (12), 180 (17), 179 (10), 178 (20),
168 (12), 167 (19), 166 (14), 165 (35), 155 (19), 154 (100);
HRMS (FAB+): calcd for C12H15NO3I (M++1),
3.1.2. (10R,5R)- or (10R,5S)-N-[(10-Methoxycarbonyl-10-
phenyl)methyl]-5-iodomethyl-1,3-oxazolidin-2-one 2a and
2b. According to the general procedure, at ꢀ20 ꢁC, the
reaction of allylamine 2 (0.26 g, 1.25 mmol) with I2
(0.29 g, 1.1 mmol, 90 mol %) yielded, after workup and
chromatography (EtOAc–hexane, 1:3–3:1), compounds 2a
(190 mg) and 2b (190 mg) as yellow oils in 92% yield. Com-
pound 2a: 1H NMR (400.16 MHz, CDCl3): d 7.42–7.23 (m,
5H, –Ph), 5.72 (s, 1H, –CHPh), 4.53 (m, 1H, –C5H–), 3.78
(s, 3H, –Me), 3.68 (dd, J = 5.9 and 8.9 Hz, 1H, –C4H2–),
3.38 (dd, J = 4.4 and 10.0 Hz, 1H, –C6H2–), 3.30 (dd,
J = 9.1 and 9.9 Hz, 1H, –C6H2–), 3.22 (t, J = 8.7 Hz, 1H,
–C4H2–) ppm. 13C NMR (100.62 MHz, CDCl3): d 170.3
(s, –CO–), 156.8 (s, –C2O–), 132.9 (s, Ph), 129.2 (d, Ph),
129.1 (d, Ph), 128.5 (d, Ph), 73.3 (d, –C5H–), 59.6 (q,
–Me), 52.6 (d, –CHPh), 47.4 (t, –C4H2–), 5.1 (t, –C6H2–)
ppm. MS (EI+): m/e (relative intensity, %) 317 (13), 316
(M+ꢀCOOCH3, 100), 272 (14), 146 (28), 144 (18),
348.0097; found, 348.0081. Melting point: 96.4–100.8 ꢁC;
23
½aꢁD ¼ ꢀ6:4 (c 0.97, CHCl3); Rf: 0.54 (EtOAc). Compound
1
3b: H NMR (400.16 MHz, CDCl3): d 7.48–7.07 (m, 5H,
–Ph), 4.88 (dd, J = 4.6 and 9.1 Hz, 1H, –CHPh), 4.58 (m,
1H, –C5H–), 4.12 (dd, J = 9.2 and 12.0 Hz, 1H, –CH2OH),
4.00 (dd, J = 4.7 and 12.0 Hz, 1H, –CH2OH), 3.73 (t,
J = 8.9 Hz, 1H, –C4H2–), 3.40 (br s, 1H, –OH), 3.28 (dd,
J = 4.1 and 10.4 Hz, 1H, –C6H2–), 3.19 (dd, J = 7.8 and
10.4 Hz, 1H, –C6H2–), 3.06 (dd, J = 6.4 and 8.9 Hz, 1H,
–C4H2–) ppm. 13C NMR (100.62 MHz, CDCl3): d 157.9
(s, –CO–), 135.9 (s, Ph), 129.0 (d, Ph), 128.4 (d, Ph),
127.4 (d, Ph), 72.4 (d, –C5H–), 61.8 (t, –CH2OH), 59.9
(d, –CHPh), 48.2 (t, –C4H2–), 6.4 (t, –C6H2–) ppm. MS
(EI+): m/e (relative intensity, %) 317 (35), 316
(M+ꢀCH2OH, 100), 272 (16), 144 (22), 117 (24), 91 (16);
HRMS (EI+): calcd for C11H11NO2I (M+ꢀCH2OH),
117 (16), 84 (13); HRMS (EI+): calcd for C11H11NO2I,
315.9834; found, 315.9836. Melting point: 96.8–98.6 ꢁC;
24
23
315.9834; found, 315.9823; ½aꢁD ¼ ꢀ43:0 (c 1.11, CHCl3);
½aꢁD ¼ ꢀ10:1 (c 0.23, CHCl3); Rf: 0.44 (EtOAc).
Rf: 0.55 (EtOAc–hexane 1:1). Compound 2b: 1H NMR
(400.16 MHz, CDCl3): d 7.41–7.23 (m, 5H, –Ph), 5.75 (s,
1H, –CHPh), 4.60 (m, 1H, –C5H–), 4.04 (t, J = 8.7 Hz,
1H, –C4H2–), 3.77 (s, 3H, –Me), 3.23 (dd, J = 4.0 and
10.4 Hz, 1H, –C6H2–), 3.09 (dd, J = 7.8 and 10.4 Hz, 1H,
–C6H2–), 2.80 (dd, J = 6.2 and 8.9 Hz, 1H, –C4H2–) ppm.
13C NMR (100.62 MHz, CDCl3): d 170.3 (s, –CO–),
156.9 (s, –C2O–), 132.9 (s, Ph), 129.2 (d, Ph), 129.2 (d,
Ph), 128.5 (d, Ph), 72.5 (d, –C5H–), 59.7 (q, –Me), 52.6
(d, –CHPh), 47.5 (t, –C4H2–), 5.9 (t, –C6H2–) ppm. MS
(EI+): m/e (relative intensity, %) 316 (M+ꢀCOOCH3,
47), 146 (36), 146 (13), 117 (12), 105 (39), 91 (10), 86
3.1.4. (10S,5S)- and (10S,5R)-5-Iodomethyl-3-(10-phenyl-
ethyl)-1,3-oxazolidin-2-one 4a and 4b. According to the
general procedure, the reaction of allylamine 4 (5.12 g,
31.75 mmol) and NIS (8.57 g, 38.10 mmol, 120 mol %)
yielded, after workup and chromatography (EtOAc–
hexane 18–40%), diastereomers 4a and 4b as a yellowish
oil and a white solid, respectively (9.65 g, 92%, in a 1.34:1
1
ratio). Compound 4a: H NMR (400.13 MHz, CDCl3): d
7.38–7.26 (m, 5H, –Ph), 5.21 (q, J = 7.1 Hz, 1H, –CHMe),
4.44 (m, 1H, –C5H–), 3.36 (dd, J = 3.8 and 10.4 Hz, 1H,
–C6H2–), 3.30–3.20 (m, 3H, 2 · –C4H2– and –C6H2–),
1.59 (d, J = 7.1 Hz, 3H, –Me) ppm. 13C NMR (100.61
MHz, CDCl3): d 156.6 (s, –CO–), 139.2 (s, Ph), 128.8 (d,
Ph), 128.0 (d, Ph), 127.0 (d, Ph), 71.6 (d, –C5H–), 51.6
(d, –CHMe), 46.0 (t, –C4H2–), 16.2 (q, –Me), 6.9 (t,
–C6H2–) ppm. MS (EI+): m/e (relative intensity, %) 331
(M+, 12), 316 (22), 204 (59), 160 (15), 146 (13), 144 (17),
117 (22), 106 (11), 105 (100), 104 (18), 103 (13), 91 (16),
88 (10), 86 (61), 84 (97), 79 (17), 78 (11), 77 (59), 69 (29);
HRMS (EI+): calcd for C12H14NO2I, 331.0069; found,
(65), 84 (100), 77 (25); HRMS (EI+): calcd for
24
C11H11NO2I, 315.9834; found, 315.9847; ½aꢁD ¼ ꢀ30:9 (c
0.38, CHCl3); Rf: 0.43 (EtOAc–hexane 1:1).
3.1.3. (10R,5R)- or (10R,5S)-N-[(20-Hydroxy-10-phenyl)-
ethyl]-5-iodomethyl-1,3-oxazolidin-2-one 3a and 3b.
According to the general procedure, the reaction of allyla-
mine 3 (118 mg, 0.67 mmol) with I2 (163 mg, 0.67 mmol,
120 mol %) yielded, after workup and chromatography
(EtOAc–hexane 1:1–2:1), compound 3a (78 mg) as a white
solid and compound 3b (63 mg) as brownish solid (63%
331.0069. UV (CHCl3): kmax 258, 253, 237 nm;
24
½aꢁD ¼ ꢀ15:7 (c 0.45, CHCl3); Rf: 0.46 (EtOAc–hexane
1
yield). Compound 3a: H NMR (400.16 MHz, CDCl3): d
1:1). Compound 4b: 1H NMR (400.13 MHz, CDCl3): d
7.38–7.26 (m, 5H, –Ph), 5.20 (q, J = 7.0 Hz, 1H, –CHMe),
4.54 (m, 1H, –C5H–), 3.61 (t, J = 8.8 Hz, 1H, –C4H2–),
3.27 (dd, J = 4.0 and 10.2 Hz, 1H, –C6H2–), 3.08 (dd,
J = 8.3 and 10.2 Hz, 1H, –C6H2–), 2.87 (dd, J = 6.3 and
9.0 Hz, 1H, –C4H2–), 1.58 (d, J = 7.1 Hz, 3H, –Me) ppm.
13C NMR (100.61 MHz, CDCl3): d 156.7 (s, –CO–),
139.0 (s, Ph), 128.7 (d, Ph), 128.0 (d, Ph), 127.1 (d, Ph),
72.1 (d, –C5H–), 51.5 (d, –CHMe), 46.0 (t, –C4H2–), 16.4
(q, –Me), 6.1 (t, –C6H2–) ppm. MS (EI+): m/e (relative
intensity, %) 331 (M+, 18), 316 (41), 272 (14), 205 (12),
204 (95), 160 (20), 149 (26), 144 (22), 131 (11), 117 (25),
106 (12), 105 (100), 104 (19), 103 (14), 91 (17), 79 (15), 77
(28); HRMS (EI+): calcd for C12H14NO2I, 331.0069;
7.48–7.07 (m, 5H, –Ph), 4.90 (dd, J = 4.8 and 9.1 Hz, 1H,
–CHPh), 4.56 (m, 1H, –C5H–), 4.13 (dd, J = 9.2 and
11.9 Hz, 1H, –CH2OH), 4.03 (dd, J = 4.7 and 11.9 Hz,
1H, –CH2OH), 3.48 (t, J = 8.8 Hz, 1H, –C4H2–), 3.38–
3.23 (m, 3H, –C4H2– and 2 · –C6H2–), 3.11 (br s, 1H,
–OH) ppm. 13C NMR (100.62 MHz, CDCl3): d 157.8 (s,
–CO–), 135.9 (s, Ph), 128.9 (d, Ph), 128.4 (d, Ph), 127.4
(d, Ph), 72.5 (d, –C5H–), 61.8 (t, –CH2OH), 59.7 (d,
–CHPh), 48.1 (t, –C4H2–), 6.3 (t, –C6H2–) ppm. MS
(EI+): m/e (relative intensity, %) 317 (26), 316
(M+ꢀCH2OH, 100), 272 (16), 144 (30), 117 (36), 104
(12), 103 (13), 91 (26), 77 (15); HRMS (EI+): calcd for
C11H11NO2I (M+ꢀCH2OH), 315.9834; found, 315.5821.