S.-J. Pyun et al. / Tetrahedron 61 (2005) 1413–1416
1415
benzophenone (indicator). Methylene chloride (CH2Cl2)
was shaken with concentrated sulfuric acid, dried over
potassium carbonate, and distilled. Commercially available
compounds were used without further purification.
17.5 Hz, 1H), 5.65–5.89 (m, 3H), 7.31–7.43 (m, 8H), 7.53
(m, 1H), 7.58–7.65 (m, 4H), 7.96–8.03 (m, 2H); 13C NMR
(125 MHz): d 19.3, 27.2, 28.5, 47.5, 59.6, 62.0, 73.4, 79.9,
115.5, 119.2, 127.9, 128.6, 129.8, 129.9, 130.4, 133.2,
133.4, 133.9, 134.2, 135.8, 136.2, 136.3, 156.2, 165.5;
HRMS m/z calcd for C36H46NO5Si 600.3145, found
600.3150.
4.1.1. (4R,5R)-4-((tert-Butyldiphenylsilyloxy)methyl)-2-
phenyl-5-vinyl-4,5-dihydrooxazole (8). trans-Oxazoline
8 was synthesized according to the Ref. 10b; colorless oil;
[a]2D5ZC24.9 (c 2.0, CHCl3); IR (neat) 3069, 2930, 2857,
4.1.4. (5R,6R)-tert-Butyl 5-(benzoyloxy)-6-((tert-butyldi-
phenylsilyloxy)methyl)-5,6-dihydropyridine-1(2H)-car-
boxylate (6). Grubbs’ catalyst (72 mg, 0.088 mmol,
5 mol%) was added to a mixture of 7 (1.05 g, 1.75 mmol)
in CH2Cl2 (70 mL). The reaction mixture was stirred at rt
for 9 h, the solvent evaporated, and the residue purified by
flash chromatography on silica gel (ethyl acetate/hexaneZ
1/15) to afford 956 mg of 6 as a colorless oil (96%);
[a]2D5ZK20.54 (c 1.0, CHCl3); IR (neat) 2931, 1723, 1699,
1411, 1108 cmK1; 1H NMR (500 MHz): d 1.04 (s, 9H), 1.52
(s, 9H), 3.51 3.58 (m, 1H), 3.77–3.91 (m, 2H), 4.34–4.42
(m, 1H), 4.57–4.75 (m, 1H), 4.87–4.92 (m, 1H), 5.60–5.77
(m, 2H), 7.31–7.45 (m, 8H), 7.53 (m, 1H), 7.66–7.75 (m,
4H), 7.80–7.83 (m, 2H)); 13C NMR (125 MHz): d 14.35,
19.42, 27.03, 28.74, 59.81, 67.11, 80.85, 82.16, 124.67,
127.94, 128.49, 128.63, 129.90, 130.06, 130.16, 130.49,
133.37, 133.51, 133.71, 135.84, 136.08, 155.07, 165.79;
HRMS m/z calcd for C34H42NO5Si 572.2832, found
572.2833.
1
1648 cmK1; H NMR (300 MHz) d 1.02 (s, 9H), 3.78 (dd,
JZ10.5, 6.5 Hz, 1H), 3.94 (dd, JZ10.5, 4.0 Hz, 1H), 4.10
(ddd, JZ6.5, 6.5, 4.0 Hz, 1H), 5.12 (dddd JZ6.5, 6.5, 1.5,
1.5 Hz, 1H), 5.23 (ddd JZ10.0, 1.5.1.5 Hz, 1H), 5.33–5.39
(ddd, JZ16.5, 1.5, 1.5 Hz, 1H), 5.91–6.02 (ddd, JZ16.5,
10.5, 6.5 Hz, 1H), 7.32–7.48 (m, 9H), 7.65–7.72 (m, 4H),
7.95–7.98 (m, 2H); 13C NMR (75 MHz) d 19.6, 27.1. 65.6,
74.2, 83.3, 116.9, 127.97, 128.02, 128.6, 129.9, 130.00,
130.04, 131.7, 133.5, 133.7, 135.1, 135.9, 136.0, 136.9,
164.3; HRMS m/z calcd for C28H32NO2Si 442.2202, found
442.2207.
4.1.2. (3R,4R)-4-(tert-Butoxycarbonylamino)-5-(tert-
butyldiphenylsilyloxy)pent-1-en-3-yl benzoate (9). The
alcohol 8 (3.50 g, 7.93 mmol) was dissolved in THF
(40 mL) and 2 N HCl (27 mL) and stirred for 16 h at rt.
The reaction mixture was cooled in an ice bath, and solid
NaHCO3 (30 g) was added. Water (130 mL) was added
followed by a solution of Boc2O (3.46 g, 15.9 mmol) in
THF (30 mL). After being stirred at room temperature for
2 h, the solution was extracted with EtOAc (3!100 mL).
The combined organic layers were washed with brine, dried
over MgSO4, concentrated, and purified by column
chromatography over silica gel (ethyl acetate/hexaneZ
1/15) to afford 9 (3.96 g, 89%) as a viscous liquid: [a]2D5Z
C10.8 (c 2.0 CHCl3); IR (neat) 2931, 2857, 1722, 1503,
4.1.5. (2R,3S,4S,5S)-tert-Butyl 3-(benzoyloxy)-2-((tert-
butyldiphenylsilyloxy)methyl)-4,5-dihydroxypiperidine-
1-carboxylate (11). To a solution of 6 (833 mg, 1.46 mmol)
in acetone (24 mL) were added N-methylmorpholine
N-oxide (50% aqueous solution, 0.68 mL, 2.91 mmol) and
the solution of 4 wt/% OsO4/water (0.46 mL, 0.073 mmol,
5 mol%). The reaction mixture was allowed to stir for 12 h,
at which time all staring material had been consumed as
judged by TLC. The reaction mixture was poured into a
solution of 15% Na2S2O3 (120 mL), extracted with CH2Cl2
(100 mL!2). The organic extract was washed with brine
(50 mL), dried with MgSO4, and evaporated in vacuo.
Purification by silica gel chromatography (ethyl acetate/
hexaneZ1/1) gave anti-diol (813 mg, 92%, single isomer)
as an oil; [a]2D5ZK6.1 (c 1.0, CHCl3); IR (neat) 3435, 2931,
1721, 1696, 1425, 1270, 1109 cmK1; 1H NMR (500 MHz):
d 1.03 (s, 9H), 1.46 (s, 9H), 3.41 (br d, JZ13.0 Hz), 3.94 (m,
2H), 4.11 (m, 1H), 4.25 (m, 1H), 4.34 (br s, 1H), 4.68 (br s,
1H), 5.45 (dd, JZ10.0, 6.5 Hz, 1H), 7.29–7.41 (m, 8H),
7.55–7.67 (m, 5H), 7.91 (m, 2H); 13C NMR (125 MHz)
14.4, 19.2, 27.3, 28.6, 45.1, 55.0, 61.5, 68.9, 70.5, 72.1,
80.8, 128.0, 128.6, 129.8, 130.0, 132.8, 132.9, 133.5, 135.7,
135.8, 155.9, 166.9; HRMS m/z calcd for C34H44NO7Si
606.2887, found 606.2883.
1
1268 cmK1; H NMR (500 MHz) d 1.06 (s, 9H), 1.36 (s,
9H), 3.71 (dd, JZ10.5, 5.5 Hz, 1H), 3.77 (dd, JZ10.5,
4.0 Hz, 1H), 4.07 (m, 1H), 4.83 (d, JZ9.5 Hz, 1H), 5.27 (d,
JZ10.0 Hz, 1H), 5.39 (d, JZ17.0 Hz, 1H), 5.79 (dd, JZ
6.0, 6.0 Hz, 1H), 5.89 (m, 1H), 7.26 (m, 1H), 7.33–7.43 (m,
7H), 7.54–7.59 (m, 3H), 7.64–7.66 (m, 2H), 8.01 (d, JZ
7.5 Hz, 2H); 13C NMR (75 MHz) d 19.3, 26.8, 27.1, 28.5,
54.7, 63.1, 74.5, 79.7, 119.2, 128.01, 128.08, 128.6, 129.9,
130.1, 133.12, 133.19, 133.3, 133.7, 135.1, 135.83, 135.89,
155.7, 165.8;. HRMS m/z calcd for C33H42NO5Si 560.2832,
found 560.2821
4.1.3. (3R,4R)-4-(Allyl(tert-butoxycarbonyl)amino)-5-
(tert-butyldiphenylsilyloxy)pent-1-en-3-yl benzoate (7).
To a solution of 9 (1.00 g, 1.79 mmol) in 16 mL of THF/
DMF (3:1) were added potassium bis(trimethylsilyl)amide
(0.5 M in toluene, 3.93 ml, 1.97 mmol), and allyl bromide
(0.19 mL, 2.14 mmol) at 0 8C. The mixture was stirred for
30 min and stirring was allowed to continue for 5 h at rt. The
reaction was quenched with a saturated aqueous NH4Cl
solution. The organic phase was separated, dried over
anhydrous MgSO4, and concentrated under reduced press-
ure. Column chromatography of the residue (ethyl acetate/
hexaneZ1/15) yielded 7 as a colorless oil (1.05 g, 98%);
[a]2D5ZC15.9 (c 1.0, CHCl3); IR (neat) 2931, 2858, 1723,
1695, 1453 cmK1; 1H NMR (500 MHz): d 1.05 (s, 9H), 1.39
(s, 9H), 3.81 (m, 2H), 3.87 (m, 1H), 3.98 (m, 1H), 4.64 (m,
1H), 4.93 (m, 1H), 5.04 (m, 1H), 5.17 (m, 1H), 5.33 (d, JZ
4.1.6. 1-Deoxygulonojirimycin(5). To a solution of 11
(742 mg, 1.23 mmol) in MeOH (8 mL) was added 6 N HCl
(30 mL, 30.64 mmol). The reaction mixture was refluxed
for 36 h and evaporated. The residue was treated with
Dowex 50WX8-400 ion-exchange resin using a sequence of
water and 3% NH4OH as eluents to yield 5 (149 mg, 75%)
as an oil; [a]2D5ZK13.3 (c 0.53, H2O) [natural
1
product([a]DZC14.0, c 0.56, H2O)]; H NMR (500 MHz,
D2O): d 2.65 (dd, JZ12.5, 10.5 Hz, 1H), 2.82 (dd, JZ12.5,
5.5 Hz, 1H), 2.93 (td, JZ6.5, 1.5 Hz, 1H), 3.52 (t, JZ