S. Hajra et al. / Tetrahedron 62 (2006) 8959–8965
8963
1.02 mmol) in 5 mL dry MeOH under hydrogen atmosphere
(1 atm) was added Pd/C (10%) (0.015 g) at 0 ꢁC under
hydrogen atmosphere and stirred for 12 h at room tempera-
ture. The reaction mixture was filtered through a half-inch
bed of Celite and the filtrate was evaporated under reduced
pressure (at<40 ꢁC) to obtain pure 8a (0.168 g, 99%) as
a colorless gummy liquid. [a]2D6 ꢀ26.0 (c 1, MeOH) [lit.9
[a]2D2 ꢀ26.5 (c 1, MeOH)]; FTIR (KBr): 3372 (br), 1592,
1519, 1355, 1204, 1164, 1018, 883, 851, 766, 741, 612,
2.30–2.05 (m, 2H), 2.00–1.80 (m, 3H), 1.55–1.30 (m, 2H),
1.15 (s, 3H), 0.97 (s, 3H); 13C NMR (CDCl3): d 166.1,
148.1, 144.4, 129.2 (2C), 123.3 (2C), 82.1, 64.8, 58.0,
52.7, 48.7, 47.7, 45.1, 44.3, 37.7, 32.5, 26.2, 20.4, 19.6;
Anal. Calcd for C20H25BrN2O6S: C, 47.91; H, 5.03; N,
5.59. Found: C, 47.88; H, 5.02; N, 5.86%.
2.1.1.9. anti-(2R,20S,30S)-N-[20-Bromo-30-methoxy-30-
(4-nitrophenyl)-propionyl]-bornanesultam (13b). Color-
less gummy liquid. [a]2D4 +5.31 (c 0.9, CHCl3); FTIR
(KBr): 3422 (br), 1686, 1522, 1384, 1347, 1302, 1216,
1166, 1136, 1116, 1066, 1041, 993, 856, 760, 699, 614,
528, 519 cmꢀ1
;
1H NMR [200 MHz, CDCl3:CD3OD
(3:1)]: d 7.70–7.20 (m, 5H), 4.50 (d, J¼8.6 Hz, 1H), 3.55–
3.10 (m, 2H), 3.00–2.55 (m, 1H); 13C NMR [50 MHz,
CDCl3:CD3OD (1:1)]: d 139.1, 128.5 (2C), 127.3 (3C),
70.1, 65.5, 62.3; Anal. Calcd for (C9H13NO2+1$H2O): C,
58.36; H, 8.16; N, 7.56. Found: C, 58.77; H, 8.10; N, 7.76%.
1
533, 498 cmꢀ1; H NMR (CDCl3): d 8.24 (d, J¼8.7 Hz,
2H), 7.62 (d, J¼8.7 Hz, 2H), 4.95 (d, J¼6.5 Hz, 1H), 4.81
(d, J¼6.5 Hz, 1H), 4.17–3.92 (m, 2H), 3.53–3.51 (m, 2H),
3.21 (s, 3H), 2.32–2.03 (m, 2H), 2.00–1.81 (m, 3H), 1.56–
1.27 (m, 2H), 1.15 (s, 3H), 0.99 (s, 3H); 13C NMR (CDCl3):
d 166.2, 148.0, 144.2, 128.9 (2C), 123.3 (2C), 82.9, 65.3,
57.7, 52.7, 48.6, 47.9, 45.7, 44.5, 37.7, 32.5, 26.7, 20.2,
19.6; Anal. Calcd for (C20H25BrN2O6S+1$H2O): C, 46.25;
H, 5.24; N, 5.39. Found: C, 46.19; H, 5.19; N, 5.48%.
2.1.1.6. anti-(2R,20R,30R)-N-[20-Bromo-30-hydroxy-30-
(4-nitrophenyl)-propionyl]-bornanesultam (10a). Color-
less gummy liquid. [a]2D5 ꢀ99.41 (c 0.8, CHCl3); FTIR
(KBr): 3495 (br), 1779, 1737, 1697, 1607, 1524, 1439,
1389, 1349, 1302, 1206, 1106, 1056, 983, 945, 857, 839,
1
754, 700, 670, 521 cmꢀ1; H NMR (CDCl3): d 8.26 (d,
J¼8.7 Hz, 2H), 7.59 (d, J¼8.7 Hz, 2H), 5.47 (d, J¼6.4 Hz,
1H), 4.76 (d, J¼6.4 Hz, 1H), 4.16–3.94 (m, 2H), 3.52 (d,
J¼1.8 Hz, 2H), 2.29–2.02 (m, 2H), 2.00–1.77 (m, 3H),
1.64–1.26 (m, 2H), 1.14 (s, 3H), 0.95 (s, 3H); 13C NMR
(CDCl3): 166.7, 147.8, 145.8, 127.9 (2C), 123.7 (2C),
75.3, 65.1, 52.6, 48.6, 47.7, 45.3, 44.3, 37.6, 32.9, 26.3,
19.9, 19.5; Anal. Calcd for C19H23BrN2O6S: C, 46.82; H,
4.76; N, 5.75. Found: C, 46.61; H, 4.98; N, 5.43%.
2.1.1.10. syn-(2R,20S,30R)-N-[20-Azido-30-methoxy-30-
(4-nitrophenyl)-propionyl]-bornanesultam (14). To
a stirred solution of 13a (0.50 g, 1.05 mmol) in 10 mL
DMF at 60 ꢁC was added NaN3 (0.11 g, 1.50 mmol) and
stirred for 8 h at 60 ꢁC. The reaction mixture was quenched
with water and extracted with EtOAc (3ꢂ50 mL). The com-
bined organic layers were dried over Na2SO4. The organic
phase was evaporated under reduced pressure and the crude
reaction mixture was then purified by flash column chroma-
tography to obtain pure 14 (0.48 g, 92%) as white solid. Mp
152–154 ꢁC; [a]D26 ꢀ76.57 (c 1.0, CHCl3); FTIR (KBr):
2140, 2111, 1711, 1607, 1519, 1333, 1216, 1166, 1135,
2.1.1.7. anti-(2R,20S,30S)-N-[20-Bromo-30-hydroxy-30-
(4-nitrophenyl)-propionyl]-bornanesultam (10b). Color-
less gummy liquid. [a]2D5 ꢀ1.19 (c 0.75, CHCl3); FTIR
(KBr): 3448 (br), 1692, 1600, 1522, 1386, 1347, 1216,
1106, 1067, 831, 761, 541 cmꢀ1 1H NMR (CDCl3):
;
1166, 1136, 1117, 1067, 856, 760, 699, 537, 499 cmꢀ1
;
d 8.21 (d, J¼6.8 Hz, 2H), 7.59 (d, J¼6.8 Hz, 2H), 4.90 (d,
J¼5.7 Hz, 1H), 4.50 (d, J¼5.7 Hz, 1H), 4.00–3.80 (m,
2H), 3.45 (s, 2H), 3.30 (s, 3H), 2.25–1.60 (m, 5H), 1.50–
1.10 (m, 2H), 0.90 (s, 3H), 0.68 (s, 3H); 13C NMR
(CDCl3): d 166.6, 148.3, 143.9, 128.8 (2C), 123.7 (2C),
83.4, 65.9, 65.2, 57.8, 53.0, 48.4, 47.5, 44.7, 37.9, 32.7,
26.4, 20.0, 19.7; Anal. Calcd for C20H25N5O6S: C, 51.83;
H, 5.44; N, 15.11. Found: C, 51.89; H, 5.34; N, 14.89%.
1H NMR (CDCl3): d 8.25 (d, J¼8.8 Hz, 2H), 7.60 (d,
J¼8.8 Hz, 2H), 5.31 (d, J¼6.7 Hz, 1H), 4.83 (d, J¼6.7 Hz,
1H), 4.17–3.92 (m, 2H), 3.56 (d, J¼2.0 Hz, 2H), 2.30–
2.00 (m, 2H), 2.00–1.76 (m, 3H), 1.68–1.25 (m, 2H), 1.15
(s, 3H), 0.98 (s, 3H); 13C NMR (CDCl3): d 166.8, 147.9,
145.9, 127.8 (2C), 123.6 (2C), 75.4, 65.4, 52.7, 48.6, 47.6,
45.2, 44.4, 37.8, 32.7, 26.1, 20.0, 19.6; Anal. Calcd for
C19H23BrN2O6S: C, 46.82; H, 4.76; N, 5.75. Found: C,
47.19; H, 5.01; N, 5.76%.
2.1.1.11. syn-(2R,3R)-[2-Amino-3-methoxy-3-(4-nitro-
phenyl)-1-propanol] (15). To a stirred solution of 14
(0.30 g, 0.72 mmol) in 5 mL THF were added 1 mL
MeOH followed by LiBH4 (0.017 g, 0.72 mmol) at 0 ꢁC
under an argon atmosphere and stirred for 1 h. The reaction
mixture was quenched with slow addition of H2O at 0 ꢁC
and extracted with EtOAc (3ꢂ40 mL). The combined
organic layers were dried over Na2SO4. The organic phase
was evaporated under reduced pressure and the crude reac-
tion mixture was taken in 5 mLTHF and 1 mL H2O mixture,
to that Ph3P (0.226 g, 0.86 mmol) was added and stirred for
12 h in dark. The reaction mixture was diluted with EtOAc
(50 mL) and evaporated under reduced pressure. The crude
compound was purified by column chromatography to afford
pure 15 (0.106 g, 82%) as a colorless gummy liquid. [a]D26
ꢀ65.59 (c 1.0, CHCl3); FTIR (KBr): 3367 (br), 1605,
2.1.1.8. anti-(2R,20R,30R)-N-[20-Bromo-30-methoxy-30-
(4-nitrophenyl)-propionyl]-bornanesultam (13a). To
a stirred solution of 9a (0.50 g, 1.28 mmol) in 5 mL
MeOH and 1.5 mL CH2Cl2 (0–5 ꢁC) were added AgNO3
(0.435 g, 2.56 mmol) and Br2 (0.409 g, 2.56 mmol) and
allowed to stir at that temperature for 20–30 min. The reac-
tion mixture was quenched with water and extracted with
EtOAc (3ꢂ50 mL). The combined organic layers were dried
over Na2SO4. The organic phase was evaporated under re-
duced pressure and the crude reaction mixture was then pu-
rified by flash column chromatography to obtain pure 13a
(0.42 g, 72%) as white solid. Mp 153–155 ꢁC; [a]D26
ꢀ89.74 (c 1.0, CHCl3); FTIR (KBr): 1696, 1608, 1524,
1456, 1384, 1347, 1218, 1167, 1136, 1101, 967, 857, 834,
1
758, 698, 558, 535, 500 cmꢀ1; H NMR (CDCl3): d 8.24
1522, 1348, 1108, 854, 829, 753, 701, 617, 542 cmꢀ1
;
(d, J¼8.7 Hz, 2H), 7.60 (d, J¼8.7 Hz, 2H), 4.79 (s, 2H),
1H NMR (CDCl3): d 8.22 (d, J¼8.7 Hz, 2H), 7.49 (d,
4.15–3.95 (m, 2H), 3.52 (d, J¼1.1 Hz, 2H), 3.22 (s, 3H),
J¼8.7 Hz, 2H), 4.25 (d, J¼6.5 Hz, 1H), 3.60–3.40 (m,