Y.-S. Hon et al. / Tetrahedron 63 (2007) 11325–11340
11333
51.29, 64.0, 173.1, 173.5, 173.7; IR (KBr, neat): 2952, 2869,
1739, 1437, 1363, 1171, 1073, 1010 cmꢁ1; MS (FAB) m/z
(relative intensity): 289 (M+1, 24), 154 (100), 136 (69),
107 (21); HRMS (FAB) calcd for C14H25O6 [M+H]+
289.1671, found 289.1661.
neat): 2937, 2860, 1733, 1460, 1253, 1185, 732 cmꢁ1; MS
(FAB) m/z (relative intensity): 359 (M+2, 37), 357 (M+1,
21), 289 (14), 195 (15), 154 (100), 137 (90); HRMS (FAB)
calcd [M+H]+ for C12H23O2Br2 357.0065, found 357.0073.
4.5.17. Benzyloxyacetic acid 2-benzyloxyethyl ester (7q).
Yield: 52%, colorless oil, Rf¼0.67 (hexane/EtOAc¼2:1). 1H
NMR (CDCl3, 400 MHz) d 3.69 (t, J¼4.8 Hz, 2H), 4.13 (s,
2H), 4.35 (t, J¼4.8 Hz, 2H), 4.45 (s, 2H), 4.63 (s, 2H),
7.27–7.37 (m, 10H); 13C NMR (CDCl3, 100 MHz) d 63.8,
67.1, 67.7, 73.1, 73.3, 127.6, 127.7, 127.9, 128.0, 128.4,
128.4, 137.1, 137.8, 170.3; IR (thin film, NaCl plates):
4.5.12. 8,8-Dimethoxyoctanoic acid 8,8-dimethoxyoctyl
ester (7k). Yield: 50%, pale yellow oil, Rf¼0.50 (ethyl
1
ether/hexane¼1:1). H NMR (CDCl3, 400 MHz) d 1.30–
1.40 (m, 12H), 1.50–1.61 (m, 10H), 2.28 (t, J¼7.6 Hz,
2H), 3.30 (s, 6H), 3.31 (s, 6H), 4.05 (t, J¼6.7 Hz, 2H),
4.34 (dt, J¼5.7 and 2.0 Hz); 13C NMR (CDCl3, 100 MHz)
d 24.3, 24.4, 24.7, 25.7, 28.5, 28.90, 28.94, 29.01, 29.2,
32.26, 32.29, 34.1, 52.4, 64.2, 104.3, 173.7; IR (KBr,
neat): 2936, 2857, 2826, 1733, 1464, 1384, 1360, 1127,
1060, 730 cmꢁ1; MS m/z (relative intensity): 281 (82), 249
(39), 187 (Mꢁ189), 155 (33), 75 (100); HRMS calcd for
C10H19O3 (Mꢁ189) 187.1321, found 187.1328.
3031, 2918, 2858, 1752, 1454, 1200, 1121, 736, 698 cmꢁ1
;
MS m/z (relative intensity): 301 (M++1, 7), 299 (M+ꢁ1,
7), 271 (12), 209 (8), 181 (12), 103 (37), 91 (100); HRMS
calcd for C18H20O4 300.1362, found 300.1356.
4.5.18. Trityloxyacetic acid 2-trityloxyethyl ester (7r).
Yield: 83%, white solid, mp 114–115 ꢀC, Rf¼0.34 (hex-
1
4.5.13. 6,6-Dimethoxyhexanoic acid 6,6-dimethoxyhexyl
ester (7l). Yield: 32%, pale yellow oil, Rf¼0.50 (hexane/
EtOAc¼1:1). 1H NMR (CDCl3, 400 MHz) d 1.30–1.34
(m, 6H), 1.52–1.61 (m, 8H), 2.25 (t, J¼7.6 Hz, 2H), 3.24
(s, 6H), 3.25 (s, 6H), 4.00 (t, J¼6.7 Hz, 2H), 4.30 (t,
J¼5.7 Hz); 13C NMR (CDCl3, 100 MHz) d 24.0, 24.1,
24.7, 25.7, 28.5, 32.0, 32.3, 34.1, 52.50, 52.53, 64.1,
104.2, 104.3, 173.5; IR (KBr, neat): 2947, 2830, 1736,
1463, 1387, 1128, 1054 cmꢁ1; MS (FAB) m/z (relative inten-
sity): 320 (M+, 2), 225 (95), 127 (100), 113 (70); HRMS
(FAB) calcd for C16H32O6 320.2203, found 320.2201.
ane/EtOAc¼10:1). H NMR (CDCl3, 400 MHz) d 3.26 (t,
J¼4.5 Hz, 2H), 3.83 (s, 2H), 4.27 (t, J¼4.5 Hz, 2H), 7.18–
7.51 (m, 30H); 13C NMR (CDCl3, 100 MHz) d 61.9, 62.7,
63.9, 86.6, 87.4, 127.0, 127.2, 127.8, 128.0, 128.6, 143.3,
143.8, 169.9; IR (thin film, NaCl plates): 3058, 2924,
1758, 1734, 1491, 1448, 1265, 1098, 738, 705 cmꢁ1; MS
m/z (relative intensity): 604 (M+, 4), 527 (45), 243 (100),
165 (66), 105 (46); HRMS calcd for C42H36O4 604.2614,
found 604.2615.
4.5.19. 3-Benzyloxypropionic acid 3-benzyloxypropyl es-
ter (7s). Yield: 61%, white solid, mp 85 ꢀC, Rf¼0.69 (hex-
ane/EtOAc¼3:1). 1H NMR (CDCl3, 400 MHz) d 1.94
(quint, J¼6.4 Hz, 2H), 2.59 (t, J¼6.4 Hz, 2H), 3.53 (t,
J¼6.4 Hz, 2H), 3.73 (t, J¼6.4 Hz, 2H), 4.22 (t, J¼6.4 Hz,
2H), 4.48 (s, 2H), 4.52 (s, 2H), 7.25–7.35 (m, 10H); 13C
NMR (CDCl3, 100 MHz) d 29.0, 35.1, 61.7, 65.6, 66.6,
72.9, 73.0, 127.5, 127.5, 127.6, 128.3, 138.1, 138.3, 171.4;
IR (thin film, NaCl plates): 3030, 2863, 1735, 1454, 1364,
1182, 1104, 737, 698 cmꢁ1; MS m/z (relative intensity):
329 (M++1, 7), 237 (39), 131 (67), 91 (100); HRMS calcd
for C20H24O4 328.1675, found 328.1673.
4.5.14. 10-Oxoundecanoic acid 10-oxoundecyl ester (7m).
Yield: 33%, white solid, mp¼53–54 ꢀC, Rf¼0.55 (hexane/
1
EtOAc¼3:1). H NMR (CDCl3, 400 MHz) d 1.21–1.25 (br
m, 18H), 1.50–1.58 (m, 8H), 2.09 (s, 6H), 2.24 (t,
J¼7.6 Hz, 2H), 2.37 (t, J¼7.4 Hz, 4H), 4.00 (t, J¼6.7 Hz,
2H); 13C NMR (CDCl3, 100 MHz) d 23.69, 23.71, 24.9,
25.8, 28.5, 28.96, 28.99, 29.02, 29.06, 29.09, 29.2, 29.6,
29.7, 34.2, 43.6, 43.7, 64.2, 173.8, 209.0, 209.1; IR (KBr,
neat): 2930, 2856, 1716, 1465, 1360, 1267, 1170, 1099,
739 cmꢁ1; MS (FAB) m/z (relative intensity): 369 (M+1,
85), 183 (100), 137 (25); HRMS (FAB) calcd for
C22H41O4 [M+H]+ 369.3018, found 369.3011.
4.5.20. (4R)-2,2-Dimethyl-[1,3]dioxolane-4-carboxylic
acid (4R)-2,2-dimethyl[1,3]dioxolan-4-ylmethyl ester
(7t).46 Yield: 60%, colorless oil, Rf¼0.60 (hexane/
4.5.15. 6-Iodohexanoic acid 6-iodohexyl ester (7n). Yield:
1
1
22%, pale yellow oil, Rf¼0.63 (hexane/EtOAc¼5:1). H
EtOAc¼1:1). H NMR (CDCl3, 400 MHz) d 1.36 (s, 3H),
NMR (CDCl3, 400 MHz) d 1.37–1.43 (m, 6H), 1.61–1.66
(m, 4H), 1.81–1.85 (m, 4H), 2.31 (t, J¼7.5 Hz, 2H), 3.18
(t, J¼6.9 Hz, 4H), 4.06 (t, J¼6.6 Hz, 2H); 13C NMR
(CDCl3, 100 MHz) d 6.5, 6.8, 23.9, 24.9, 28.4, 29.9, 30.1,
33.1, 33.3, 34.0, 64.2, 173.4; IR (KBr, neat): 2933, 2858,
1732, 1458, 1427, 1351, 1265, 1207, 1182, 738 cmꢁ1; MS
(FAB) m/z (relative intensity): 453 (M++1, 38), 211 (35),
154 (100), 137 (81); HRMS (FAB) calcd for C12H22O2I2
[M+H]+ 452.9782, found 452.9785.
1.41 (s, 3H), 1.43 (s, 3H), 1.50 (s, 3H), 3.73 (dd, J¼7.5
and 5.0 Hz, 1H), 4.06–4.33 (m, 6H), 4.60 (dd, J¼7.5 and
5.0 Hz, 1H); 13C NMR (CDCl3, 100 MHz) d 25.20, 25.4,
25.8, 26.6, 65.2, 66.2, 67.2, 73.3, 73.9, 109.8, 111.4,
170.9; [a]2D4.3 ꢁ6.8 (c 0.012, CHCl3); IR (thin film, NaCl
plates): 2988, 2938, 2886, 1762, 1373, 1256, 1241,
1103 cmꢁ1; MS m/z (relative intensity): 261 (M++1, 5),
245 (100), 203 (43), 101 (36), 43 (31).
4.5.21. (4R,5R)-2,2-Dimethyl-5-vinyl[1,3]dioxolane-4-
carboxylic acid (4R,5R)-2,2-dimethyl-5-vinyl[1,3]dioxo-
lan-4-ylmethyl ester (7u). Yield: 71%, pale yellow oil,
Rf¼0.44 (hexane/EtOAc¼5:1). 1H NMR (CDCl3,
400 MHz) d 1.38 (s, 3H), 1.41 (s, 3H), 1.50 (s, 3H), 1.65
(s, 3H), 3.94 (dd, J¼11.6 and 7.6 Hz, 1H), 4.21 (dd,
J¼11.5 and 4.8 Hz, 1H), 4.35 (ddd, J¼7.3, 7.3, and
4.5 Hz, 1H), 4.66 (dd, J¼6.9 and 6.8 Hz, 1H), 4.71 (d,
4.5.16. 6-Bromohexanoic acid 6-bromohexyl ester (7o).
Yield: 70%, pale yellow oil, Rf¼0.49 (hexane/
1
EtOAc¼10:1). H NMR (CDCl3, 400 MHz) d 1.34–1.58
(m, 6H), 1.59–1.63 (m, 4H), 1.81–1.85 (m, 4H), 2.28 (t,
J¼7.5 Hz, 2H), 3.37 (t, J¼6.8 Hz, 4H), 4.03 (t, J¼6.6 Hz,
2H); 13C NMR (CDCl3, 100 MHz) d 24.0, 25.0, 27.5, 27.6,
28.3, 32.3, 32.5, 33.4, 33.6, 33.9, 64.1, 173.3; IR (KBr,