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M. R. Chaulagain et al. / Tetrahedron Letters 45 (2004) 7791–7794
21. Prepared from 6 in 80% overall yield by acetonide
formation (CSA, (MeO)2CMe2) and saponification
(LiOH, THF–H2O).
27. Use of the Sharpless asymmetric dihydroxylation to try
and improve the erythro to threo ratio is currently under
investigation.
22. Spectral data for ester 15: [a]D = ꢀ11.1 (c 1.0, CHCl3); FT-
IR (neat) 3063, 3029, 2976, 2930, 2854, 2117, 1738, 1695,
1453, 1389, 1374, 1257, 1166, 1102, 1068, 1027, 735,
28. The stereochemistry of the erythro and threo-isomers was
assigned based on correlation with literature precedent,
see Ref. 29.
697cmꢀ1
;
1H NMR (500MHz, CDCl3): d 7.33–7.25 (m,
29. This is precedented, see: Krysan, D. J.; Rockway, T. W.;
Haight, A. R. Tetrahedron: Asymmetry 1994, 5, 625–632.
30. Spectral data for N-Boc erythro-diol: [a]D = ꢀ7.4 (c 1.0,
CHCl3); FT-IR (neat): 3397, 2916, 2850, 1660, 1524, 1454,
15H, ArH), 5.91 (ddd, 1H, J = 17.5, 10.0, 7.5Hz, H-2),
5.38 (ddd, 1H, J = 5.5, 5.5, 3.5Hz, H-5), 5.32 (br s, 1H, H-
1), 5.29 (s, 1H, H-1), 4.73 (d, 1H, J = 11.5Hz, OCH2Ph),
4.58–4.54 (m, 2H, 2 · OCH2Ph) 4.48 (d, 1H, J = 12.5Hz,
OCH2Ph), 4.43 (d, 1H, J = 11.5Hz, OCH2Ph), 4.32 (d,
1H, J = 11Hz, OCH2Ph), 3.93–3.87 (m, 1H, H-3), 3.87–
3.85 (m, 1H, 1 · H-10), 3.85–3.81 (m, 2H, H-9, H-4), 3.68–
3.63 (m, 1H, 1 · H-10), 3.55 (d, 2H, J = 5.5Hz, 2 · H-6),
2.35–2.25 (m, 1H, 1 · H-7), 2.25–2.15 (m, 1H, 1 · H-7),
2.10–1.90 (m, 1H, 1 · H-8), 1.88–1.78 (m, 1H, 1 · H-8),
1.54 (s, 3H, CH3), 1.48 (br s, 12H, CH3, OC(CH3)3); 13C
NMR (125MHz, CDCl3, data for major rotamer only): d
172.29, 138.44, 138.08, 135.81, 135.71, 172.70, 172.54,
128.60, 128.56, 128.48, 128.25, 120.09, 119.98, 94.08,
93.56, 79.51, 74.82, 73.33, 71.85, 71.76, 70.40, 68.42,
66.91, 57.02, 56.96, 31.16, 28.88, 28.67, 28.46, 27.83, 23.34,
15.52, 14.46; HRMS (ES): calcd for C40H51NO8Na (M)+
696.3507, found 696.3499.
1366, 1167, 1107, 732, 696cmꢀ1 1H NMR (500MHz,
;
CDCl3): d 7.38–7.26 (m, 20H, ArH), 4.95 (br s, 1H,
BocNH), 4.93 (app d, 2H, J = 11.5Hz, 2 · OCH2Ph), 4.74
(d, 1H, J = 11.5Hz, OCH2Ph), 4.69 (d, 1H, J = 12.5Hz,
OCH2Ph), 4.65 (d, 1H, J = 11Hz, OCH2Ph), 4.63 (d, 1H,
OCH2Ph), 4.48 (d, 1H, J = 12Hz, OCH2Ph), 4.40 (d, 1H,
J = 12Hz, OCH2Ph), 3.89 (br s, 1H, H-6), 3.76–3.70 (m,
1H, H-9), 3.68 (dd, 1H, J = 9.0, 9.0Hz, H-2), 3.58 (dd, 1H,
J = 9.0, 6.5Hz, H-3), 3.59–3.57 (m, 1H, H-6), 3.54–3.47
(m, 2H, H-11, H-4), 3.44 (dd, 1H, J = 6.0, 3.5Hz, H-10),
3.34 (ddd, 1H, J = 9.0, 5.5, 5.5Hz, H-5), 3.27, (ddd, 1H,
J = 8.0Hz, H-1), 3.12 (br s, 1H, OH), 2.42 (br s, 1H, OH),
1.96 (dddd, 1H, J = 15.5, 9.5, 8.0, 1.5Hz, H-8), 1.87 (m,
1H, J = 15, 10, 7.5, 2.5Hz, H-8), 1.71–1.53 (m, 4H,
1 · CH2, 2 · H-7), 1.52–1.20 (m, 22H, 11 · CH2), 1.26 (s,
9H, (CH3)3), 0.89 (t, 3H, J = 7.0Hz, CH3); 13C NMR
(125MHz, CDCl3): d 156.93, 138.71, 138.61, 138.54,
137.92, 128.69, 128.67, 128.61, 128.49, 128.38, 128.21,
128.08, 127.93, 127.91, 127.81, 85.00, 79.70, 79.33, 79.15,
77.88, 77.44, 77.27, 75.64, 74.58, 73.95, 73.67, 73.01, 72.68,
69.79, 52.57, 32.17, 29.94, 29.63, 27.86, 26.19, 22.94, 14.38;
HRMS (ES): calcd for C58H83NO9Na (M)+ 960.5960,
found 960.6000.
23. Scholl, M.; Ding, S.; Lee, C. W.; Grubbs, R. H. Org. Lett.
1999, 1, 953–956.
24. Spectral data for C-glycoside 18: [a]D = +24.7 (c 1.0,
CHCl3); FT-IR (neat) 3433, 2924, 2856, 1693, 1454, 1390,
1364, 1254, 1173, 1091, 1027, 735, 697cmꢀ1 1H NMR
;
(500MHz, CDCl3): d 7.39–7.27 (m, 15H, ArH), 4.85 (d,
1H, J = 12Hz, OCH2Ph), 4.72 (d, 1H, J = 11.5Hz,
OCH2Ph), 4.63 (d, 1H, J = 11.5Hz, OCH2Ph), 4.55–4.44
(m, 3H, OCH2Ph), 4.05, 3.95 (m, 2H, 2 · H-6), 3.90 (dd,
1H, J = 8.5, 6.0Hz, H-3), 3.80–3.71 (m, 2H, H-2, H-4),
3.60–3.58 (m, 2H, 2 · H-10), 3.39–3.34 (dd, 1H, J = 10,
2.5Hz, H-5), 3.13 (dd, 1H, J = 8.0, 8.0Hz, H-1), 2.34 (br s,
1H, OH), 2.01–1.82 (m, 2H, 2 · H-7), 1.59 (s, 3H, CH3),
1.54 (s, 3H, CH3), 1.50–1.42 (m, 2H, 2 · H-8), 1.44 (s, 9H,
(CH3)3); 13C NMR (125MHz, CDCl3): d 171.40, 128.66,
128.47, 128.34, 128.13, 127.97, 108.90, 93.44, 84.47, 80.45,
74.60, 73.77, 73.11, 72.66, 71.76, 70.59, 69.13, 67.19, 66.09,
60.63, 57.65, 31.81, 30.26, 28.72, 27.83, 27.01, 23.54, 22.88,
21.29, 15.50, 14.42, 14.36; HRMS (ES): calcd for
C39H51NO8Na (M)+ 684.3506, found 684.3478.
31. Takikawa, H.; Muto, S.; Mori, K. Tetrahedron 1998, 54,
3141–3150.
32. Data for analog 5: [a]D = +44.8 (c 1.0, CDCl3); FT-IR
1
(neat) 3394, 2922, 2852, 2360, 1646, 1465, 1270cmꢀ1; H
NMR (500MHz, CD3OD, 10% CHCl3): d 6.84 (1H,
J = 8.5Hz, NH), 4.09 (ddd, 1H, J = 11.0, 7.0, 5.0Hz, H-9),
3.72 (dd, 1H, J = 8.5Hz, H-2), 3.67–3.58, (m, 2H, H-3, H-
4), 3.49–3.37 (m, 5H, 2 · H-6, H-5, H-1, H-10), 3.14–3.09
(m, 1H, H-11), 2.24–1.10 (m, 78H, 2 · H-7, 2 · H-8,
37 · CH2), 0.88 (app t, 6H, J = 7.0Hz, 2 · CH3); 13C
NMR (125MHz, CDCl3): d 158.19, 124.60, 123.90,
121.67, 116.53, 116.42, 55.80, 33.51, 31.92, 30.25, 29.60,
29.32, 25.54, 24.89, 22.59, 18.03, 13.40; HRMS (ES):
calcd for C51H101NO8Na (M)+ 878.7419, found 878.
7479.
25. The corresponding gluco-analog of this compound has
been prepared previously by us: Postema, M. H. D.; Piper,
J. L. Org. Lett. 2003, 5, 1721–1723.
26. For an excellent review on the diastereoselection of
osmylation of allylic systems, see: Cha, J. K.; Kim, N.-S.
Chem. Rev. 1995, 95, 1761–1795.
33. Valeriote, F. A.; Grieshaber, C. K.; Media, J.; Pie-
traszkiewicz, H.; Hoffmann, J.; Pan, M.; McLaughlin, S.
J. Exp. Ther. Oncol. 2002, 7, 228–236.