H. Xiong et al. / Tetrahedron Letters 43 (2002) 4449–4453
4453
22.7, 31.1, 39.1, 39.5, 56.8, 62.6, 86.6, 158.7, 203.5; IR
(thin film) cm−1 2957s, 2928s, 2872s, 1755s, 1524w,
1483w, 1467m, 1415s, 1381m, 1239s, 1199s; mass spectra
(CI) m/e (% relative abundance) 230 (70) M++H, 198(42),
130(15), 128(33), 105(100), 88(38), 75(19); m/e Calcd for
C11H20NO4 230.1392, found 230.1398. 18a/b: Rf=0.29
2.16 (m, 2H), 3.42 (s, 3H), 4.34 (dd, 1H, J=7.5, 9.0 Hz),
4.71 (t, 1H, J=9.0 Hz), 4.87 (dd, 1H, J=7.5, 9.0 Hz),
5.15 (s, 1H), 7.27–7.37 (m, 5H); 13C (500 MHz, CDCl3) l
13.9, 22.2, 22.3, 31.0, 39.0, 56.7, 56.8, 70.4, 86.5, 128.4,
128.98, 129.40, 136.7, 158.8, 204.3; IR (thin film) cm−1
2954m, 1758s, 1374m, 1037w; mass spectrum (EI): m/e
(% relative intensity) 274 (1) (M+−OMe), 206(100),
162(8), 135(14), 86(14). 35a: Rf=0.53 (50% ether in hex-
1
(50% EtOAc in hexane); [h]2D0 −75.2 (c 0.5 in CH2Cl2); H
NMR (500 MHz, CDCl3) major l 1.20–2.20 (m, 8H),
3.15 (s, 3H), 4.01–4.04 (m, 1H), 4.17 (dd, 1H, J=2.5, 8.0
Hz), 4.60 (t, 1H, J=8.0 Hz), 4.95 (dd, 1H, J=2.5, 8.0
Hz), 7.27–7.41 (m, 5H); 13C (300 MHz, CDCl3) major l
21.9, 22.0, 30.2, 30.9, 50.3, 58.2, 58.3, 70.5, 91.5, 126.2,
128.4, 129.0, 142.2, 158.1; IR (thin film) cm−1 2943m,
1748s, 1334m, 1045w; mass spectrum (GC MS): m/e (%
relative intensity) 259 (3) (M+−MeOH), 162 (65), 104
(100), 91 (23). 23: Rf=0.40 (50% EtOAc in hexane); [h]D20
−72.8 (c 0.50 in CH2Cl2); 1H NMR (500 MHz, CDCl3)
l 1.55–1.68 (m, 4H), 2.42–2.45 (m, 2H), 2.95–2.98 (m,
2H), 4.30 (dd, 1H, J=3.5, 8.5 Hz), 4.70 (t, 1H, J=8.5
Hz), 5.43 (dd, 1H, J=3.5, 8.5 Hz), 7.41–7.27 (m, 5H),
9.73 (t, 1H, J=1.5 Hz); 13C (500 MHz, CDCl3) l 21.4,
23.5, 35.2, 43.5, 57.6, 70.0, 125.9, 128.7, 129.2, 139.1,
153.8, 172.2, 202.2; IR (thin film) cm−1 3034m, 2944m,
1717s, 1435w, 1041m; mass spectrum (LC MS): m/e (%
relative intensity) 276 (6) (M+H+), 230 (45), 186 (67), 164
(66), 120 (100). 30a: Rf=0.41 (50% EtOAc in hexane);
[h]2D0 −52.2 (c 0.54 in CH2Cl2); 1H NMR (500 MHz,
CDCl3) l 2.18 (s, 3H), 3.21 (s, 3H), 4.29 (dd, 1H, J=7.0,
9.0 Hz), 4.71 (t, 1H, J=9.0 Hz), 4.93 (dd, 1H, J=7.0, 9.0
Hz), 5.05 (s, 1H), 7.26–7.40 (m, 5H); 13C (500 MHz,
CDCl3) l 27.0, 57.0, 57.9, 70.7, 88.2, 127.4, 129.0, 129.1,
138.4, 153.8, 202.6; IR (thin film) cm−1 2932m, 1756s,
1459m, 1002w; mass spectrum (GC MS): m/e (% relative
intensity) 218 (2) (M+−OMe), 206(100), 162(13), 135(23),
104(22), 103(35), 86(37), 77(12). 30b: Rf=0.25 (50%
EtOAc in hexane); [h]2D0 −153.9 (c 0.69 in CH2Cl2); 1H
NMR (500 MHz, CDCl3) l 1.73 (s, 3H), 3.43 (s, 3H),
4.37 (dd, 1H, J=7.5, 9.0 Hz), 4.72 (t, 1H, J=9.0 Hz),
4.88 (dd, 1H, J=7.5, 9.0 Hz), 5.12 (s, 1H), 7.27–7.38 (m,
5H); 13C (500 MHz, CDCl3) l 26.1, 56.8, 57.0, 70.3, 86.8,
128.5, 129.0, 129.7, 136.4, 158.6, 202.2; IR (thin film)
cm−1 2932m, 1756s, 1459m, 1002w; mass spectrum (GC
MS): m/e (% relative intensity) 218 (2) (M+−OMe),
206(100), 162(13), 135(28), 104(25), 103(35), 86(36),
77(12). 31a: Rf=0.68 (50% EtOAc in hexane); [h]2D0 −61.1
1
ane); [h]2D0 41.3 (c 0.45 in CHCl3); H NMR (500 MHz,
CDCl3) l 0.70 (q, 6H, J=8.0 Hz), 0.92 (t, 3H, J=7.0
Hz), 0.99 (t, 9H, J=8.0 Hz), 1.30–1.33 (m, 4H), 1.95–2.00
(m, 1H), 2.11–2.18 (m, 1H), 3.19 (s, 3H), 4.19 (dd, 1H,
J=6.0, 9.0 Hz), 4.58 (t, 1H, J=9.0 Hz), 4.78 (dd, 1H,
J=6.0, 9.0 Hz), 4.85 (dt, 1H, J=1.0, 8.0 Hz), 5.21 (d,
1H, J=1.0 Hz), 7.26–7.33 (m, 5H); 13C (500 MHz,
CDCl3) l 5.3, 6.7, 13.9, 22.6, 24.6, 31.7, 55.6, 57.3, 70.7,
85.9, 112.2, 126.9, 128.3, 128.4, 140.6, 142.8, 159.2; IR
(thin film) cm−1 2969m, 2879m, 1774s, 1404m, 1239m,
1171m; mass spectrum (LC MS): m/e (% relative inten-
sity) 420(78) (M+H+), 388(100), 274(8). 36a: Rf=0.48
(50% EtOAc in hexane); [h]2D0 −137.5 (c 0.40 in CHCl3);
1H NMR (500 MHz, CDCl3) l 0.90 (t, 3H, J=7.0 Hz),
1.05–1.75 (m, 10H), 2.68 (ddd, 1H, J=6.0, 6.0, 6.0 Hz),
4.08 (dd, 1H, J=5.0, 9.0 Hz), 4.40 (dd, 1H, J=4.0, 7.0
Hz), 4.51 (ddd, 1H, J=2.0, 6.0, 6.0 Hz), 4.74 (t, 1H,
J=9.0 Hz), 4,83 (d, 1H, J=4.0 Hz), 5.04 (dd, 1H, J=5.0,
9.0 Hz), 7.25–7.41 (m, 5H); 13C (500 MHz, CDCl3) l
13.9, 22.7, 24.4, 25.7, 27.0, 29.5, 55.7, 58.3, 65.5, 71.2,
77.8, 79.9, 126.2, 128.8, 129.3, 140.5, 159.1, 204.4. IR
(thin film) cm−1 2957m, 2929m, 1761s, 1718s, 1457m,
1412m, 1399m, 1074m, 704m; mass spectrum (LC MS):
m/e (% relative intensity) 344(38) (M+H+), 326(64),
276(27), 232(29), 202(23), 176(78), 163(100), 132(30),
120(42). 37 (mixed with some pre-hydrogenated cycload-
duct): Rf=0.55 (50% EtOAc in hexane); 1H NMR (500
MHz, CDCl3) pre-hydrogenated cycloadduct: l 0.85 (t,
3H, J=7.0 Hz), 1.00–1.95 (m, 6H), 2.78 (dt, 1H, J=7.5,
6.0 Hz), 4.06 (dd, 1H, J=4.0, 9.0 Hz), 4.70 (m, 1H), 4.75
(dd, 1H, J=2.0, 6.0 Hz), 4.80 (t, 1H, J=9.0 Hz), 4.87
(dd, 1H, J=2.0, 4.5 Hz), 5.01 (d, 1H, J=4.5 Hz), 5.14
(dd, 1H, J=2.0, 6.0 Hz), 6.14 (dd, 1H, J=2.0, 6.0 Hz),
7.23–7.44 (m, 5H); 37: l 0.91 (t, 3H, J=7.5 Hz), 1.00–
1.95 (m, 6H), 3.44 (d, 1H, J=18.0 Hz), 3.64 (dd, 1H,
J=7.0, 8.0 Hz), 4.14 (t, 1H, J=8.0 Hz), 4.30 (d, 1H,
J=18.0 Hz), 4.73 (t, 1H, J=8.0 Hz), 4.90 (t, 1H, J=8.0
Hz), 6.06 (d, 1H, J=3.5 Hz), 6.24 (dd, 1H, J=2.0, 3.5
Hz), 7.13–7.44 (m, 6H); 13C (500 MHz, CDCl3) l as a
mixture 13.77, 13.83, 22.3, 22.7, 24.7, 28.8, 29.2, 29.5,
49.2, 49.8, 55.6, 57.6, 59.7, 66.0, 70.1, 71.1, 80.4, 81.5,
107.7, 110.6, 126.1, 127.2, 129.0, 129.1, 129.2, 129.5,
132.9, 133.7, 136.7, 140.7, 142.2, 150.9, 158.5, 159.6,
202.2, 202.8; IR (thin film) cm−1 2958m, 2928m, 1762s,
1723m, 1410m, 1399m, 1077m, 706m; mass spectrum
(GC MS): m/e (% relative intensity) Peak 1: 341(30)
(M+), 281(5), 176(95), 150(60), 132(65), 91(78), 81(100);
Peak 2: 341(5) (M+), 281(7), 207(100), 176(10).
1
(c 0.73 in CH2Cl2); H NMR (500 MHz, CDCl3) l 0.88
(t, 3H, J=6.0 Hz), 1.21–1.32 (m, 4H), 1.51–1.56 (m, 2H),
2.47 (t, 2H, J=7.5 Hz), 3.19 (s, 3H), 4.29 (dd, 1H,
J=5.5, 9.0 Hz), 4.70 (t, 1H, J=9.0 Hz), 4.92 (dd, 1H,
J=5.5, 9.0 Hz), 5.09 (s, 1 H), 7.27–7.40 (m, 5H); 13C (500
MHz, CDCl3) l 13.9, 22.4, 22.7, 31.2, 39.3, 57.0, 57.9,
70.7, 88.2, 127.4, 128.9, 129.0, 138.5, 158.6, 204.8; IR
(thin film) cm−1 2932m, 1758s, 1362m, 986w; mass spec-
trum (EI): m/e (% relative intensity) 274 (2) (M+−OMe),
207(13), 206(100), 162(9), 135(15), 104(14), 86(15). 31b:
Rf=0.58 (50% EtOAc in hexane); [h]2D0 −123.5 (c 0.70 in
CH2Cl2); 1H NMR (500 MHz, CDCl3) l 0.81 (t, 3H,
J=7.5 Hz), 0.98–1.04 (m, 3H), 1.06–1.18 (m, 3H), 2.03–