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Helvetica Chimica Acta – Vol. 88 (2005)
J=10.2, 4.6, 1 HÀC(8)); 3.00 (t-like, Jꢀ10.0, 1 HÀC(8)); 1.44 (d, J=6.1, Me). 13C-NMR (75.5 MHz, CDCl3):
135.8 (s, C(5)); 77.9 (d, C(7)); 65.7, 64.8 (2t, C(2), C(3)); 40.1 (t, C(8)); 19.0 (q, Me). CI-MS (NH3): 165 (5),
164 (7), 163 (100, [M+H]+), 106 (25). Anal. calc. for C6H10O3S (162.21): C 44.43, H 6.21; found C 44.08, H 5.79.
3.2. With (R)-2-Phenyloxirane ((R)-2). Reaction of 3 (104 mg, 1 mmol) with (R)-2 (240 mg, 2 mmol) in 15
ml of anh. CH2Cl2 and 4.5 g of SiO2 at 0–58, 2 d, and CC (SiO2, hexane/Et2O 3 :1) yielded 76 mg (34%) of (S)-8-
phenyl-1,4,6-trioxa-9-thiaspiro[4.4]nonane (9). Colorless oil. [a]2D3 =À10.3. IR (film): 3061w, 3029w, 2975m,
2898s, 1602w, 1493s, 1453s, 1359w, 1346w, 1302w, 1276m, 1247m, 1210s, 1147vs, 1119vs, 1079s, 1063s, 1030vs,
1
1004vs, 950vs, 861w, 797w, 762s, 700vs. H-NMR (600 MHz, CDCl3): 7.48–7.46 (m, 2 arom. H); 7.35–7.32 (m,
2 arom. H); 7.29–7.26 (m, 1 arom. H); 4.86 (dd, J=6.9, 5.9, HÀC(8)); 4.41 (dd, J=9.2, 5.7, 1 HÀC(7));
4.20–4.09 (m, 2 HÀC(2), 2 HÀC(3)); 4.08 (dd, J=9.2, 7.0, 1 HÀC(7)). 13C-NMR (150.9 MHz, CDCl3): 138.4
(s, 1 arom. C); 137.1 (s, C(5)); 128.8 (d, 2 arom. CH); 128.0 (d, 1 arom. CH); 127.9 (d, 2 arom. CH); 75.5 (t,
C(7)); 65.6, 65.4 (2t, C(2), C(3)); 54.2 (d, C(8)). CI-MS (NH3): 227 (6), 226 (13), 225 (100, [M+H]+), 106
(12). Anal. calc. for C11H12O3S (224.28): C 58.91, H 5.39; found C 59.31, H 5.72.
4. Reaction of 1,3-Dimethylimidazolidine-2-thione (4a) with (R)-2. Reaction of 4a (97 mg, 0.74 mmol) with
(R)-2 (150 mg, 1.25 mmol) in 10 ml of anh. CH2Cl2 and 3.6 g of SiO2 at 08, 2 h, and CC (SiO2, hexane) yielded 84
mg (83%) of (S)-2-phenylthiirane ((S)-10) in 97% ee (HPLC) as a colorless oil and 1,3-dimethylimidazolidin-2-
one (11a; Table 1).
An analogous experiment was carried out with (À)-(R)-2 (91.9% ee (HPLC)). The isolated (+)-(S)-10
showed [a]2D3 +29.2 (c=1.17, in heptane; 93.5% ee (HPLC)).
5. Reaction of 3-Phenyloxazolidine-2-thione (4b) with (RS)-2. Reaction of 4b (94 mg, 0.5 mmol) with (RS)-2
(120 mg, 1 mmol) in 10 ml of anh. CH2Cl2 and 3.0 g of SiO2 at 08, 10 h, and CC (SiO2, hexane/AcOEt) yielded 45
mg (66%) of (RS)-10 and 64 mg (79%) of 3-phenyloxazolidin-2-one (11b; Table 1).
6. Reaction of 3-Phenylthiazolidine-2-thione (4c) with (RS)-2. Reaction of 4c (49 mg, 0.25 mmol) with (RS)-
2 (60 mg, 0.5 mmol) in 10 ml of anh. CH2Cl2 and 1.5 g of SiO2 at 08, 10 h, yielded 19.6 mg (58%) of (RS)-10 and
1
41 mg (92%) of 3-phenylthiazolidin-2-one (11c) based on the H-NMR analysis of the reaction mixture and a
weighed amount of 1,1,2,2-tetrachloroethane as a standard (Table 1).
7. Reaction of 4a with 1,2-Epoxycyclohexane (=7-Oxabicyclo[4.1.0]heptane; 7). Reaction of 4a (104 mg, 0.8
mmol) with 7 (297 mg, 3 mmol) in 15 ml of anh. CH2Cl2 and 4.0 g of SiO2 at 08, 40 h, yielded 89 mg (98%) of 7-
thiabicyclo[4.1.0]heptane (12) based on the 1H-NMR analysis of the reaction mixture and a weighed amount of
1,1,2,2-tetrachloroethane as a standard.
8. Reaction of Imidazolidine-2-thione (5) with (RS)-2. To the suspension of 5 (102 mg, 1 mmol) in anh.
CH2Cl2 (18 ml) and Et2O (2 ml) under an N2 atmosphere, 2.2 equiv. of BF3 ·Et2O were added at À668, which
led to an almost homogenous soln. After stirring the mixture for 15 min at À668, 480 mg (4 mmol) of (RS)-2
were added dropwise over 20 min. After stirring for an additional 10 min, the reaction was quenched by addition
of H2O, and the mixture was washed with sat. aq. NaCl soln. (3×). The combined org. layers were dried (MgSO4)
and evaporated in vacuo. The residue was washed with hexane (4×), filtered, and dried under high vacuum: 290
mg (95%) of 1,3-bis[(E)-2-phenylethen-1-yl]imidazolidine-2-thione (13). Yellow powder. M.p. 2488 (dec.). IR
(KBr): 3054m, 3023m, 2953w, 2890w, 1641s, 1597m, 1574w, 1475s, 1450s, 1428s, 1386s, 1291s, 1261s, 1207m,
1182m, 1124w, 1084m, 1074m, 1031w, 978w, 952s, 939s, 904w, 869m, 841w, 830w, 821m, 760m, 748s, 691s. 1H-
NMR (600 MHz, CDCl3): 8.25 (d, J=14.7, 2 HÀC(1’)); 7.41–7.39 (m, 4 arom. H); 7.32–7.30 (m, 4 arom. H);
7.21–7.18 (m, 2 arom. H); 5.93 (d, J=14.7, 2 HÀC(2’)); 4.02 (s, 2 HÀC(4), 2 HÀC(5)). 13C-NMR (150.9
MHz, CDCl3): 176.3 (s, C(2)); 136.4 (s, 2 arom. C); 129.0 (d, 4 arom. C); 126.97, 126.95 (2d, 2 arom. C, 2
C(1’)); 126.0 (d, 4 arom. C); 112.0 (d, 2 C(2’)); 44.4 (t, C(4), C(5)). CI-MS (NH3): 309 (11), 308 (23), 307
(100, [M+H]+), 277 (7).
Crystals of 13 suitable for the X-ray crystal-structure determination were grown from CH2Cl2/hexane.
9. Reaction of 1,3-Diacetylimidazolidine-2-thione (6) with (RS)-2. The soln. of 6 (186 mg, 1 mmol) and (RS)-
2 (600 mg, 5 mmol) in xylene was heated to reflux for 38 h. After evaporation of the solvent in vacuo, 10 ml of
Et2O/hexane (2 :8) were added to the solid residue. The mixture was stirred vigorously for 5 min and then fil-
tered. The filter cake was washed with hexane (3×). CC (SiO2, hexane/ AcOEt 5 :1) of the filter cake yielded 111
mg (45%) of 1-acetyl-3-[(E)-2-phenylethen-1-yl]imidazolidine-2-thione (14) and 20 mg (7%) of 13.
Data of 14. Colorless crystals. M.p. 169.3–169.78. IR (KBr): 3063w, 3046w, 3031w, 3002w, 2980w, 2949w,
2911w, 1682s, 1635s, 1597m, 1575w, 1487s, 1470s, 1448m, 1420s, 1388s, 1371s, 1324m, 1268s (br.), 1201s, 1100m,
1088m, 1071m, 1039m, 1021m, 963m, 942s, 902w, 861w, 836w, 825m, 752s, 718w, 690s. 1H-NMR (300 MHz,
CDCl3): 8.20 (d, J=14.8, HÀC(1’)); 7.42–7.20 (m, 5 arom. H); 6.05 (d, J=14.8, HÀC(2’)); 4.16–4.10 (m, 2
HÀC(5)); 3.88–3.83 (m, 2 HÀC(4)); 2.88 (s, Me). 13C-NMR (75.5 MHz, CDCl3): 175.9 (s, C=S); 171.7 (s,
C=O); 135.5 (s, 1 arom. C); 128.7 (d, 2 arom. C); 127.2, 126.2 (2d, 1 arom. C, C(1’)); 125.9 (d, 2 arom. C);