T. Taguchi et al. / Journal of Fluorine Chemistry 97 (1999) 157±159
159
(ice bath), the reaction mixture was diluted with H2O
(30 ml) and extracted with AcOEt (30 ml  2). The organic
extracts were successively washed with NaHCO3 aq and
brine, and dried over MgSO4. Removal of solvent under
reduced pressure gave the crude selenoxide, which was
heated in toluene at 808C for 18 h. Puri®cation by silica
gel column (hexane: AcOEt3:1) gave (2S,10S)-4 (L-
F2MCPG-I N-Boc Me ester) (52.3 mg, 18%) and
(2S,3S,4R)-5 (50.4 mg, 17%), respectively. (2S,10S)-4: col-
(131 mg, 0.59 mmol) and tributylphosphine (0.14 ml,
0.59 mmol) gave the selenide (2R,10S,20S)-2 (153 mg,
79%), which was treated with 30% H2O2 (0.5 ml) in
THF at 08C for 2 h to give the crude selenoxide. Upon
heating the selenoxide (161 mg) in toluene at 808C for 12 h
and subsequent puri®cation by silica gel column (hexane:
AcOEt1: 1) afforded (2R,10S)-4 (D-F2MCPG-II N-Boc
Me ester, 35.7 mg, 42%). (2R,10S)-4: colorless needles;
25:4
D
m.p. 59±608C; ꢁ
27.5 (c 1.79, CHCl3). 1H-NMR
orless needles; m.p. 48.5±508C; ꢁ25:6 97.9 (c 0.67, CHCl3).
(400 MHz, CDCl3) ꢀ; 1.44 (9 H, s), 2.58 (1 H, brs), 3.81
(3 H, s), 4.33 (1 H, brs), 5.08 (1 H, brs), 5.82 (1 H, s), 6.12 (1
H, d, J3.2 Hz). 13C-NMR (75.5 MHz, CDCl3) ꢀ; 28.2, 30.4
(t, J12.3 Hz), 50.7, 52.7, 80.4, 105.9 (dd, J294.3,
291.0 Hz), 114.8, 127.7 (t, J7.4 Hz), 154.8, 170.8.
19F-NMR (376.5 MHz, CDCl3) ꢀ; ±64.70 (1 F, d,
J180.4 Hz), ±77.3 (1 F, d, J180.4 Hz). MS(EI) m/z;
278 (M1), 221, 178, 162, 118. Anal. Calcd. for
C12H17F2NO4: C, 51.98; H, 6.18; N, 5.05. Found: C,
52.24; H, 6.22; N, 4.81.
D
1H-NMR (400 MHz, CDCl3) ꢀ; 1.45 (9 H, s), 2.56 (1 H, m),
3.80 (3 H, s), 4.33 (1 H, brs), 5.15 (1 H, brs), 5.81 (1 H, s),
6.11 (1 H, d, J3.2 Hz). 13C-NMR (100.6 MHz, CDCl3) ꢀ;
28.2, 30.9 (t, J12.4 Hz), 50.7, 52.8, 80.5, 105.8 (t,
J292.7 Hz), 114.1, 128.3 (t, J7.5 Hz), 154.9, 170.7.
19F-NMR (376.5 MHz, CDCl3) ꢀ; ±64.31 (1 F, dd,
J178.8, 5.5 Hz), ±75.49 (1 F, d, J178.8 Hz). IR
(KBr): 1744, 1681 cm 1. MS(EI) m/z; 278 (M1), 221,
178, 162, 118. Anal. Calcd. for C12H17F2NO4: C, 51.98; H,
6.18; N, 5.05. Found: C, 52.21; H, 6.30; N, 4.73. (2S,3S,4R)-
25:6
5: yellow oil; ꢁ
±103.9 (c 1.80, CHCl3). 1H-NMR
D
(400 MHz, CDCl3) ꢀ; 1.40 (5 H, s), 1.44 (4 H, s), 2.24±
2.39 (2 H, m), 3.72±3.96 (2 H, m), 3.78 (3 H, s), 4.52 (0.55
H, s), 4.66 (0.45 H, s). 13C-NMR (100.6 MHz, CDCl3) ꢀ;
25.4 (t, J12.0 Hz), 26.2 (t, J11.9 Hz), 28.2, 28.3, 28.6 (t,
J12.8 Hz), 29.4 (t, J12.6 Hz), 45.8, 52.5, 52.6, 58.7,
59.0, 80.8, 112.0 (dd, J297.4, 277.9 Hz), 152.9, 153.5,
170.9, 171.1. 19F-NMR (376.5 MHz, CDCl3) ꢀ; ±66.25
(0.45 F, dt, J164.9, 11.7 Hz), ±66.44 (0.55 F, dt,
J164.6, 12.1 Hz), ±92.16 (0.55 F, d, J164.6 Hz), ±
92.19 (0.45 F, d, J164.9 Hz). IR (neat): 1756,
1707 cm 1. MS(EI) m/z; 278 (M1), 222, 176. Anal. Calcd.
for C12H17F2NO4: C, 51.98; H, 6.18; N, 5.05. Found: C,
52.59; H, 6.26; N, 4.96.
References
[1] M. Lautens, W. Klute, W. Tam, Chem. Rev. 96 (1996) 49.
[2] D.M.T. Chan, in: B.M. Trost (Ed.), Comprehensive Organic
Synthesis, vol. 5, Pergamon Press, New York, 1991, p. 271.
[3] A. Brandi, A. Goti, Chem. Rev. 98 (1998) 589.
[4] W.R. Dolbier Jr., C.R. Burkholder, Tetrahedron 41 (1985) 297.
[5] M.-t. Lai, L.-d. Liu, H.-w. Liu, J. Am. Chem. Soc. 113 (1991)
7388.
[6] D. Li, Z. Guo, H.-w. Liu, J. Am. Chem. Soc. 118 (1996) 275.
[7] T. Taguchi, M. Kurishita, A. Shibuya, K. Aso, Tetrahedron 53 (1997)
9497.
[8] W.R. Dolbier Jr., S.F. Sellers, B.H. Al-Sader, B.E. Smart, J. Am.
Chem. Soc. 102 (1980) 5398.
[9] A. Shibuya, A. Sato, T. Taguchi, Bioorg. Med. Chem. Lett. 8 (1998)
1979.
3.3. D-F2MCPG-II N-Boc Me ester (2R,10S)-4
In a similar procedure as above, reaction of (2R,10S,20R)-1
(114 mg, 0.39 mmol) with 2-nitrophenyl selenocyanate