A. Hamdach et al. / Tetrahedron 62 (2006) 6392–6397
6395
(Na2SO4) and concentrated to dryness. The complex mix-
tures were purified by silica gel column chromatography
using hexane/EtOAc mixtures as eluent.
3.0 Hz, H-5), 4.76 (d, 1H, J¼7.0 Hz, H-4), 7.34 (m, 2H),
7.42 (m, 3H); 13C NMR (75.4 MHz, CDCl3) d 12.4 (q),
37.4 (t), 60.7 (d), 61.9 (t), 82.3 (d), 127.3 (d), 129.3 (d),
129.6 (d), 138.0 (s), 157.9 (s). HREI-MS m/z calcd for
[M]+ C12H15NO3 221.1051, found: 221.1033.
4.3.1. From 3-amino-3-phenyl-1,2-propanediol18 (1a).
The reaction with diphosgene afforded 1,3-oxazolidin-2-
one (2a) (70%); the reaction with phosgene 1,3-oxazoli-
din-2-one (2a) (75%).
4.3.3.3. 5-Hydroxy-3-ethyl-4-phenyltetrahydro-1,3-
oxazin-2-one (4c). White solid. Mp 132–133 ꢁC. IR
1
(KBr): nmax 3380, 3272, 1672 cmꢀ1; H NMR (400 MHz,
4.3.1.1. cis-5-Hydroxymethyl-4-phenyl-1,3-oxazoli-
din-2-one (2a). Colourless oil. IR (KBr): nmax 3336,
CDCl3) d 1.17 (t, 3H, J¼7.0 Hz), 2.87 (dq, 1H, J¼14.0,
7.0 Hz, CH2–N), 3.77 (dq, 1H, J¼14.0, 7.0 Hz, CH2–N),
4.02 (d, 1H, J¼2.0 Hz, H-5), 4.15 (dt, 1H, J¼12.0, 2.0 Hz,
H-6eq), 4.21 (dd, 1H, J¼11.8, 1.3 Hz, H-6ax), 4.62 (br s,
1H, H-4), 7.28 (m, 2H), 7.37 (m, 3H); 13C NMR
(75.4 MHz, CDCl3) d 12.2 (q), 43.6 (t), 65.3 (d), 66.8 (t),
67.2 (d), 126.5 (d), 128.4 (d), 129.1 (d), 138.5 (s), 153.7
(s); HRFAB-MS m/z calcd for [M+1]+ C12H16NO3
222.1130, found: 222.1120.
1
1745 cmꢀ1; H NMR (400 MHz, CDCl3) d 3.17 (dd, 1H,
J¼12.5, 4.0 Hz, CH2–O), 3.31 (dd, 1H, J¼12.5, 4.0 Hz,
CH2–O), 4.87 (td, 1H, J¼8.5, 4.0 Hz, H-5), 5.03 (d, 1H,
J¼8.5 Hz, H-4), 6.31(br s, NH), 7.26 (m, 2H), 7.36 (m,
3H); 13C NMR (75.4 MHz, CDCl3) d 57.8 (d), 62.0 (t),
80.8 (d), 127.4 (d), 128.9 (d), 129.0 (d), 135.9 (s), 159.9
(s); HREI-MS m/z calcd for [M]+ C10H11NO3 193.0738,
found: 193.0719.
4.3.3.4. Ethyl-[(2-oxo-1,3-dioxolan-4-yl)(phenyl)methyl]-
carbamoyl chloride (6c). White solid. Mp 85–86 ꢁC
4.3.2. From 3-methylamino-3-phenyl-1,2-propanediol13
(1b). The reaction with diphosgene afforded a mixture of
cis-1,3-oxazolidin-2-one (2b) (16%), trans-1,3-oxazolidin-
2-one17 (3b) (45%) and tetrahydro-1,3-oxazin-2-one17 (4b)
(8%); the reaction with phosgene afforded cis-oxazolidinone
(2b) (70%).
1
(hexane/chloroform). IR (KBr): nmax 1814, 1728 cmꢀ1; H
NMR (400 MHz, CDCl3) d 1.12 (t, 3H, J¼7.0 Hz, CH2–
CH3), 3.30 (dq, 1H, J¼21.0, 7.0 Hz, CH2–CH3), 3.61 (dq,
1H, J¼21.0, 7.0 Hz, CH2–CH3), 4.33 (dd, 1H, J¼8.5,
7.0 Hz, H-5), 4.66 (t, 1H, J¼8.5 Hz, H-5), 4.87 (d,
J¼8.5 Hz, 1H, Ph-CH-N), 5.52 (m, 1H, H-4), 7.42 (s, 5H);
13C NMR (100 MHz, CDCl3) d 14.0 (q), 45.9 (t), 65.4 (d),
67.3 (t), 76.7 (d), 126.5 (d), 128.4 (d), 129.4 (d), 134.8 (s),
150.9 (s), 154.1 (s); HREI-MS m/z calcd for [M]+
C13H14NO4Cl 283.0611, found: 283.0590.
4.3.2.1. cis-5-Hydroxymethyl-3-methyl-4-phenyl-1,3-
oxazolidin-2-one (2b). White solid. Mp 69–70 ꢁC. IR:
nmax 3502, 1744 cmꢀ1; 1H NMR (400 MHz, CDCl3) d 2.77
(s, 3H), 3.18 (dd, 1H, J¼12.0, 3.0 Hz, CH2–O), 3.32 (m,
1H, CH2–O), 4.82 (m, 2H, H-4+H-5), 7.17 (m, 2H), 7.39
(m, 3H); 13C NMR (75.4 MHz, CDCl3) d 29.6 (q), 62.1 (t),
63.4 (d), 77.8 (d), 127.6 (d), 129.1 (d), 129.4 (d), 133.6
(s), 158.6 (s); HREI-MS m/z calcd for [M]+ C11H13NO3
207.0853, found: 207.0895.
4.3.4. From 3-benzylamino-3-phenyl-1,2-propanediol21
(1d). The reaction with diphosgene afforded a mixture of
trans-1,3-oxazolidin-2-one (3d) (18%), tetrahydro-1,3-oxa-
zin-2-one (4d) (11%) and 1,3-dioxolan-2-one (5d) (40%);
the reaction with phosgene afforded 1,3-dioxolan-2-one
(5d) (70%).
4.3.3. From 3-ethylamino-3-phenyl-1,2-propanediol13
(1c). The reaction with diphosgene afforded a mixture of
cis-1,3-oxazolidin-2-one (2c) (16%), trans-1,3-oxazolidin-
2-one (3c) (30%) and tetrahydro-1,3-oxazin-2-one (4c)
(12%); the reaction with phosgene afforded 1,3-oxazoli-
din-2-one (2c) (20%) and carbamoyl chloride 6c (46%).
4.3.4.1. trans-5-Hydroxymethyl-3-benzyl-4-phenyl-
1,3-oxazolidin-2-one (3d). Yield 18%. Oil. IR (KBr): nmax
1
3422, 1744 cmꢀ1; H NMR (400 MHz, CDCl3) d 3.50 (dd,
1H, J¼12.7, 3.7 Hz, CH2–O), 3.55 (d, 1H, J¼15.0 Hz,
CH2–N), 3.75 (dd, 1H, J¼12.5, 3.0 Hz, CH2–O), 4.26 (m,
1H, H-5), 4.39 (d, 1H, J¼7.0 Hz, H-4), 4.74 (d, 1H,
J¼15.0 Hz, CH2–N), 7.04 (m, 2H), 7.15 (m, 6H), 7.30 (m,
2H); 13C NMR (75.4 MHz, CDCl3) d 46.1 (t), 60.3 (d),
61.8 (t), 82.5 (d), 127.4 (d), 127.8 (d), 128.1 (d), 128.5 (d),
128.9 (d), 129.5 (d), 135.3 (s), 137.5 (s), 158.2 (s); HREI-
MS m/z calcd for [M]+ C17H17NO3 283.1208, found:
283.1211.
4.3.3.1. cis-5-Hydroxymethyl-3-ethyl-4-phenyl-1,3-ox-
azolidin-2-one (2c). Colourless oil. IR (KBr): nmax 3430,
1
1742 cmꢀ1; H NMR (500 MHz, CDCl3) d 1.19 (t, 3H,
J¼7.0 Hz), 2.75 (dq, 1H, J¼14.0, 7.0 Hz, CH2–N), 3.10
(dd, 1H, J¼12.5, 4.5 Hz, CH2–O), 3.10 (dd, 1H, J¼12.5,
8.0 Hz, CH2–O), 3.53 (dq, 1H, J¼14.0, 7.0 Hz, CH2–N),
4.76 (m, 1H, H-5), 4.84 (d, 1H, J¼8.5, H-4), 7.05 (m, 2H),
7.40 (m, 3H); 13C NMR (75.4 MHz, CDCl3) d 12.7 (q),
37.3 (t), 60.8 (d), 62.5 (t), 78.1 (d), 127.8 (d), 129.3 (d),
129.5 (d), 133.9 (s), 158.1 (s); HREI-MS m/z calcd for
[M]+ C12H15NO3 221.1051, found: 221.1040.
4.3.4.2. 3-Benzyl-5-hydroxy-4-phenyl-1,3-oxazinan-2-
one (4d). White solid. Mp 200–201 ꢁC. IR (KBr): nmax
3442, 1704 cmꢀ1 1H NMR (400 MHz, CDCl3) d 3.65
;
(d, 1H, J¼15.5 Hz, CH2N), 4.16 (dt, 1H, J¼13.0, 2.0 Hz,
H-6eq), 4.34 (dd, 1H, J¼13.0, 1.6 Hz, H-6ax), 4.59 (br s,
1H, H-4), 4.68 (m, 1H, H-5), 5.47 (d, 1H, J¼15.5 Hz,
CH2–N), 7.30 (m, 5H, Ph–CH2N), 7.46 (m, 5H, Ph-C4);
13C NMR (75.4 MHz, CDCl3) d 50.7 (t), 60.8 (d), 64.1 (t),
73.1 (d), 126.7, 128.1 (d), 128.3 (d), 129.1 (d), 129.3 (d),
129.9 (d), 136.1 (s), 136.3 (s), 152.8 (s); HREI-MS m/z calcd
for [M]+ C17H17NO3 283.1208, found: 283.1114.
4.3.3.2. trans-5-Hydroxymethyl-3-ethyl-4-phenyl-1,3-
oxazolidin-2-one (3c). Colourless oil. IR (KBr): nmax
1
3419, 1740 cmꢀ1; H NMR (500 MHz, CDCl3) d 1.09 (t,
3H, J¼7.0 Hz), 2.61 (br s, 1H, OH), 2.89 (dq, 1H, J¼14.0,
7.0 Hz, CH2–N), 3.52 (dq, 1H, J¼14.0, 7.0 Hz, CH2–N),
3.70 (dd, 1H, J¼13.0 and 3.5 Hz, CH2–O), 3.97 (dd, 1H,
J¼13.0, 3.0 Hz, CH2–O), 4.34 (ddd, 1H, J¼7.0, 3.5,