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J. Dambacher et al. / Tetrahedron 60 (2004) 2097–2110
(c 1.45, CHCl3); 1H NMR d 7.28 (dt, COCHvCH, J¼15.3,
1.5 Hz, 1H), 7.15 (dt, COCHvCH, J¼15.3, 7.0 Hz, 1H),
4.53 (dd, NCH, J¼7.4, 1.5 Hz, 1H), 4.28 (dd, OCH2, J¼9.2,
1.4 Hz, 1H), 4.24 (dd, OCH2, J¼9.2, 7.6 Hz, 1H), 1.96 (dd,
CH3CH, J¼7.0, 1.5 Hz, 3H), 0.94 (s, t-Bu, 9H); 13C NMR d
165.5, 154.9, 147.0, 122.2, 65.4, 61.0, 36.1, 26.8, 18.7;
FTIR (film, cm21) 1778, 1700, 1634; HRMS (EI) calcd for
[C11H18NO3]þ 212.1287 (MHþ), found 212.1282.
J¼15.4, 1.5 Hz, 1H), 7.14 (dt, CHvCHCH2, J¼15.4,
7.0 Hz, 1H), 4.51 (dd, NCH, J¼7.6, 1.8 Hz, 1H), 4.29 (dd,
OCH2, J¼9.2, 1.8 Hz, 1H), 4.24 (dd, OCH2, J¼9.2, 7.6 Hz,
1H), 2.28 (m, CHvCHCH2, 2H), 1.48 (qu, CH2, 2H), 1.36
(se, CH2CH3, J¼7.6 Hz, 2H), 0.94 (s, t-Bu, 9H), 0.92 (t,
CH3CH2, J¼7.2 Hz, 3H); 13C NMR d 165.7, 154.9, 152.0,
120.6, 65.4, 61.0, 36.1, 32.6, 30.4, 25.8, 22.5, 14.0; FTIR
(film, cm21) 1778, 1688, 1634; HRMS (EI) calcd for
[C14H23NO3] 253.1678, found 253.1679.
4.5.3. N-(20E-Butenoyl)-4S-phenylmethyl-1,3-oxazolidin-
2-one (3).34 Flash chromatography (50% Et2O in pentane;
Rf 0.50) yielded 91% (880 mg) of 3 as a white solid, mp
83.3–83.9 8C; [a]D20 þ70.18 (c 0.85, CHCl3) {lit.34 mp
4.5.7. N-(20E-Heptenoyl)-4S-phenylmethyl-1,3-oxazolidin-
2-one (7). Flash chromatography (30% Et2O in pentane; Rf
0.35) yielded 70% (817 mg) of 7 as a white solid; mp 58–
60 8C; [a]2D0 þ90.388 (c 1.31, CHCl3); 1H NMR d 7.36–7.31
(m, Ar–H and olefinic, 2H), 7.29–7.17 (m, Ar–H and
olefinic, 5H), 4.73 (m, N–CH, 1H), 4.21 (dd, CH2O, J¼9.0,
8.1 Hz, 1H), 4.16 (dd, CH2O, J¼9.0, 3.1 Hz, 1H), 3.34 (dd,
CH2Ph, J¼13.4, 3.3 Hz, 1H), 2.86 (dd, CH2Ph, J¼13.4,
9.5 Hz, 1H), 2.31 (dt, CH2–CHvCH, J¼7.0, 6.5 Hz, 2H),
1.50 (m, CH2CH2, 2H), 1.38 (m, CH2CH3, 2H), 0.92 (t,
CH3CH2, J¼7.5 Hz, 3H); 13C NMR d 165.4, 153.7, 152.2,
135.6, 129.7, 129.2, 127.5, 120.6, 66.3, 55.6, 38.2, 32.6,
30.4, 22.5, 14.0; FTIR (KBr, cm21) 1778, 1678, 1631;
HRMS (EI) calcd for [C17H21NO3] 287.1521, found
287.1528. Anal. calcd for C17H21NO3: C, 71.06; H, 7.37;
N, 4.87. Found: C, 71.40; H, 7.26; N, 4.53.
1
85.0–86.0 8C; [a]D þ77.98, (c 2.00, CHCl3)}; H NMR d
7.36–7.31 (m, Ar–H, 2H), 7.30–7.17 (m, Ar–H and
olefinic, 5H), 4.73 (m, NCH, 1H), 4.21 (dd, CH2O, J¼9.0,
7.7 Hz, 1H), 4.18 (dd, CH2O, J¼9.0, 2.9 Hz, 1H), 3.33 (dd,
CH2Ph, J¼13.4, 3.2 Hz, 1H), 2.80 (dd, CH2Ph, J¼13.4,
9.5 Hz, 1H), 1.98 (d, CH3CH, J¼5.6 Hz, 3H); 13C NMR d
165.2, 153.7, 147.2, 135.6, 129.7, 129.2, 127.5, 122.1, 66.3,
55.5, 38.1, 18.8; FTIR (KBr, cm21) 1778, 1690, 1636;
HRMS (EI) calcd for [C14H15NO3] 245.1052, found
245.1054.
4.5.4. N-(20E-Butenoyl)-5S-triphenylmethoxymethyl-2-
pyrrolidinone (4).18,36 Flash chromatography (40%
EtOAc in hexane; Rf 0.4) yielded 82% of 4 as a colorless
solid, mp 115–116 8C; [a]2D0 285.18 (c 1.20, CHCl3) {lit.18,36
mp 116–117 8C; [a]2D0 286.28 (CHCl3)}; 1H NMR d
7.31–7.26 (m, Ar–H, 6H), 7.22 (dq, CH–CO, J¼15.2,
1.7 Hz, 1H), 7.22–7.17 (m, Ar–H, 6H), 7.17–7.12 (m,
Ar–H, 3H), 7.02 (dq, CH–CH3, J¼15.2, 6.8 Hz, 1H),
4.46 (m, N–CH, 1H), 3.50 (dd, CH2O, J¼9.8, 4.0 Hz,
1H), 3.07 (dd, CH2O, J¼9.8, 2.8 Hz, 1H), 2.89 (ddd,
a-CH2, J¼17.8, 10.0, 10.3 Hz, 1H), 2.42 (ddd, a-CH2,
J¼17.8, 9.9, 1.7 Hz, 1H), 2.06–1.97 (m, CH2CH2, 2H),
1.90 (dd, CH3, J¼7.0, 1.7 Hz, 3H); 13C NMR d 176.6,
165.8, 145.6, 143.7, 128.6, 127.9, 127.1, 124.1, 87.0,
64.2, 56.8, 33.4, 21.2, 18.5; FTIR (KBr, cm21) 1732,
1678, 1634; HRMS (DCI/NH3) calcd for [C28H28NO3]þ
426.2069 (MHþ), found 426.2074.
4.5.8. N-(20E-Heptenoyl)-5S-triphenylmethoxymethyl-2-
pyrrolidinone (8).18 Flash chromatography (30% Et2O in
pentane; Rf 0.4) yielded 72% (0.94 g) of 8 as a light yellow
oil; [a]2D0 266.28 (c 1.13, CHCl3) {lit.18 [a]2D0 264.58
1
(CHCl3)}; H NMR d 7.38–7.34 (m, Ar–H, 6H), 7.33 (dt,
CH–CO, J¼15.4, 1.4 Hz, 1H), 7.27–7.22 (m, Ar–H, 6H),
7.21–7.16 (m, Ar–H, 3H), 7.10 (dt, CH2CHvCHCO,
J¼15.4, 7.0 Hz, 1H), 4.51 (m, N–CH, 1H), 3.56 (dd, CH2O,
J¼9.8, 4.0 Hz, 1H), 3.14 (dd, CH2O, J¼9.8, 2.7 Hz, 1H),
2.94 (ddd, a-CH2, J¼17.8, 10.0, 10.0 Hz, 1H), 2.46 (ddd,
a-CH2, J¼17.8, 9.9, 2.0 Hz, 1H), 2.29 (dq, CH2CHvCH,
J¼7.0, 1.3 Hz, 2H), 2.07–1.96 (m, CH2-ring, 1H), 1.96–
1.89 (m, CH2-ring, 1H), 1.53–1.44 (m, CH2-chain, 2H),
1.43–1.33 (m, CH2-chain, 2H), 0.92 (t, CH3CH2, J¼7.3 Hz,
3H); 13C NMR d 176.4, 166.2, 150.9, 143.7, 128.8, 127.1,
127.3, 122.7, 87.2, 64.4, 57.0, 33.6, 32.6, 30.6, 22.5, 21.3,
14.1; FTIR (neat, cm21) 1733, 1675, 1634; HRMS (FAB
DCM/NBA/NaCl) calcd for [C31H33NO3Na]þ 490.2358,
found 490.2379.
4.5.5. N-(20E-Heptenoyl)-4R-phenyl-1,3-oxazolidin-2-
one (5). Flash chromatography (20% EtOAc in petroleum
ether; Rf 0.50) yielded 72% (525 mg) of 5 as a white solid;
mp 71–73 8C; [a]2D0 2118.78 (c 1.63, CHCl3); H NMR d
1
7.40–7.35 (m, Ar–H, 2H), 7.34–7.29 (m, Ar–H, 3H),
7.25 (dt, COCHvCH, J¼15.3, 1.5 Hz, 1H), 7.09 (dt,
COCHvCH, J¼15.3, 7.0 Hz, 1H), 5.48 (dd, NCH, J¼8.8,
3.9 Hz, 1H), 4.69 (dd, OCH2, J¼8.8, 8.8 Hz, 1H), 4.27 (dd,
OCH2, J¼8.8, 3.9 Hz, 1H), 2.26 (m, CH2CHvCH, 2H),
1.44 (qu, CH2, J¼7.2 Hz, 2H), 1.34 (se, CH2CH3, J¼
7.2 Hz, 2H), 0.9 (t, CH3, J¼7.2 Hz, 3H); 13C NMR d 165.0,
154.0, 152.6, 139.4, 129.4, 128.9, 126.2, 120.4, 70.1, 57.9,
32.5, 30.3, 22.4, 13.9; FTIR (film, cm21) 1780, 1686, 1636;
HRMS (EI) calcd for [C16H19NO3] 273.1365, found
273.1357. Anal. calcd for C16H19NO3: C, 70.31; H, 7.01;
N, 5.12. Found: C, 70.46; H, 6.84; N, 4.91.
4.5.9. N-(30-Phenyl-20E-propenoyl-)-4R-phenyl-1,3-oxa-
zolidin-2-one (9).9a Flash chromatography (15% EtOAc
in petroleum ether; Rf 0.40) yielded 88% (642 mg) of 9 as a
white solid. Recrystallization (EtOAc/Hexanes) afforded
9 as white crystals; mp 169–170 8C; [a]2D0 23.98 (c 0.85,
CHCl3) {lit.9a mp 169–171 8C; [a]2D2 þ3.48 for the
S-enantiomer, (c 0.74, CHCl3)}; 1H NMR d 7.93 (d,
PhCH, J¼15.5 Hz, 1H), 7.78 (d, PhCHCH, J¼15.5 Hz,
1H), 7.61–7.57 (m, Ar–H, 2H), 7.42–7.37 (2m, Ar–H,
5H), 7.37–7.32 (2m, Ar–H, 3H), 5.56 (dd, NCH, J¼8.7,
3.8 Hz, 1H), 4.74 (dd, OCH2, J¼8.7, 8.7 Hz, 1H), 4.32 (dd,
OCH2, J¼8.7, 3.8 Hz, 1H); 13C NMR d 165.0, 154.0, 146.9,
139.2, 134.7, 130.9, 129.4, 129.1, 128.9, 128.9, 126.2,
117.1, 70.2, 58.1; FTIR (film, cm21) 1778, 1684, 1622;
HRMS (EI) calcd for [C18H15NO3] 293.1052, found
293.1042.
4.5.6. N-(20E-Heptanoyl)-4S-tert-butyl-1,3-oxazolidin-2-
one (6). Flash chromatography (50% Et2O in pentane, Rf
0.50) yielded 88% (395 mg) of 6 as a clear syrup; [a]D20
1
þ76.78 (c 1.0, CHCl3); H NMR d 7.26 (dt, CHvCHCH2,