The Journal of Organic Chemistry
Page 12 of 18
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IR(neat) ν max: 3726, 3704, 3623, 3599, 3019, 2925, 2855, 1725, 1218, 771 cm-1; H
NMR(CDCl3, 400 MHz) δ 7.96‒8.04 (m, 2 H), 7.60 (t, J = 7.1 Hz, 1 H), 7.46 (t, J = 7.5 Hz, 2
H), 7.29‒7.40 (m, 5 H), 5.90 (ddt, J = 17.0, 10.0, 7.0 Hz, 1 H), 5.66 (dd, J = 8.2, 3.4 Hz, 1 H),
5.57 (d, J = 7.7 Hz, 1 H), 5.05‒5.25 (m, 5 H), 4.57 (dd, J = 12.1, 2.9 Hz, 1 H), 4.47 (t, J = 6.8
Hz, 1 H), 4.37 (dd, J = 12.0, 8.1 Hz, 1 H), 4.30 (dd, J = 8.2, 1.2 Hz, 1 H), 3.83 (d, J = 7.6 Hz,
1 H), 3.15 (s, 1 H), 2.39 (dt, J = 13.7, 6.7 Hz, 1 H), 2.26 (dt, J = 14.0, 7.1 Hz, 1 H), 2.05 (s, 3
H), 2.01‒2.04 (m, 3H), 0.71 (s, 9 H), 0.01 (s, 3 H), −0.14 (s, 3H); 13C NMR(CDCl3, 101 MHz)
δ 170.7, 170.4, 165.7, 156.0, 136.3, 133.8, 129.8, 128.6, 128.1, 118.5, 74.5, 73.1, 70.4, 69.2,
66.9, 61.2, 53.2, 38.3, 31.9, 29.7, 29.4, 25.6, 22.7, 20.8, 17.8, 14.1, −4.5, −4.8; HRMS (EI+)
[(M)+] m/z calcd for C34H47NO10Si 657.2969; found 657.2969.
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(2R,3R,4R,5R,6R)-3-(Benzoyloxy)-5-(((benzyloxy)carbonyl)amino)-4-((tert-
butyldimethylsilyl)oxy)-6-hydroxynon-8-ene-1,2-diyl diacetate (20b). Rf = 0.35 (hexanes:ethyl
acetate = 2:1); [α]D20 +3.6 (c 0.3, CHCl3); IR (neat) ν max: 3726, 3704, 3623, 3599, 3019, 1725,
1218, 771 cm-1; 1H NMR (CDCl3, 400 MHz) δ 7.94 (d, J = 7.6 Hz, 2 H), 7.49 (t, J = 7.3 Hz, 1
H), 7.34 (t, J = 7.6 Hz, 2 H), 7.15‒7.24 (m, 5 H), 5.78 (ddt, J = 17.0, 10.0, 7.0 Hz, 1 H), 5.64
(t, J = 4.8 Hz, 1 H), 5.33 (quin, J = 3.5 Hz, 1 H), 5.18 (d, J = 8.7 Hz, 1 H), 5.09 (d, J = 12.6
Hz, 2 H), 4.90‒5.00 (m, J = 5.3 Hz, 2 H), 4.49 (dd, J = 12.2, 2.2 Hz, 1 H), 4.25 (dd, J = 5.2,
3.1 Hz, 1 H), 4.19 (dd, J = 12.1, 7.2 Hz, 1 H), 3.83 (td, J = 8.6, 2.7 Hz, 1 H), 3.66 (t, J = 8.2
Hz, 1 H), 2.36‒2.44 (m, 2 H), 2.15 (quin, J = 7.5 Hz, 1 H), 1.97 (s, 3 H), 1.92 (s, 3 H), 0.70 (s,
9 H), 0.00 (s, 3 H), −0.12 (s, 3 H); 13C NMR (CDCl3, 101 MHz) δ 170.7, 170.4, 165.7, 156.3,
134.1, 133.5, 129.8, 128.6, 128.4, 127.8, 119.1, 73.3, 71.4, 70.0, 66.7, 61.9, 57.9, 39.0, 29.7,
25.7, 21.0, 20.7, 17.9, −0.1, −4.4, −4.7; HRMS (EI+) [(M)+] m/z calcd for C34H47NO10Si
657.2969; found 657.2964.
(2R,3R,4R,5R,6S)-3-(Benzoyloxy)-5-(((benzyloxy)carbonyl)amino)-4,6-bis((tert-
butyldimethylsilyl)oxy)non-8-ene-1,2-diyl diacetate (21). To a solution of compound 20a (301
mg, 0.45 mmol) in CH2Cl2 (4.7 mL), tert-butyldimethylsilyl trifluoromethanesulfonate (0.38
mL, 1.64 mmol) and 2,6-lutidine (0.19 mL, 1.64 mmol) were added at 0 °C and stirred at room
temperature for 20 min. The reaction was quenched with NH4Cl, diluted with EtOAc, and the
organic phase was washed with saturated brine, dried with MgSO4, and concentrated in vacuo.
Purification by silica gel chromatography gave product 21 (323 mg, 0.42 mmol, 93% yield) as
a colorless oil. Rf = 0.51 (hexanes:ethyl acetate = 4:1); [α]D20 +21.2 (c 0.5, CHCl3); IR (neat) v
max 3725, 3704, 3623, 3599, 3019, 2926, 2854, 1724, 1217, 770 cm−1; 1H NMR (CDCl3, 400
MHz) δ 7.83‒7.93 (m, 2 H), 7.38‒7.45 (m, 1 H), 7.24‒7.31 (m, 2 H), 6.99‒7.22 (m, 5 H), 5.66
(ddt, J = 17.8, 9.8, 7.5 Hz, 1 H), 5.50 (dd, J = 8.1, 2.8 Hz, 1 H), 5.24 (ddd, J = 8.2, 5.3, 3.3 Hz,
1 H), 4.80‒4.98 (m, 4 H), 4.25 (dd, J = 12.3, 3.3 Hz, 1 H), 3.90‒4.04 (m, 3 H), 3.78 (ddd, J =
10.0, 7.5, 2.1 Hz, 1 H), 2.01‒2.17 (m, 2 H), 1.93 (s, 3 H), 1.83 (s, 3 H), 0.75 (s, 9 H), 0.72 (s,
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9 H), −0.09 to 0.13 (m, 12 H); C NMR (CDCl3, 101 MHz) δ 170.6, 169.6, 165.6, 156.0,
136.7, 133.3, 133.2, 129.7, 128.4, 128.2, 128.0, 118.7, 71.7, 71.4, 69.7, 66.8, 62.2, 54.7, 39.5,
26.0, 25.9, 21.0, 20.6, 18.0, –3.2, –4.3; HRMS (FAB+) [(M + H)+] m/z calcd for C40H62NO10Si2
772.3912; found 772.3914.
(2R,3R,4R,5R,6S)-3-(Benzoyloxy)-5-(((benzyloxy)carbonyl)amino)-4,6-bis((tert-
butyldimethylsilyl)oxy)-8,9-dihydroxynonane-1,2-diyl diacetate (22). OsO4 in t-BuOH (2.5%
wt., 0.19 mL, 0.02 mmol) and NMO (8.7 mg, 0.75 mmol) were added to a solution of 21 (288
mg, 0.37 mmol) in acetone/H2O (5:1) solvent (1.86 mL) at 0 °C. After 8 h, the reaction mixture
was poured into a solution of saturated aq. Na2SO4. The mixture was washed with EtOAc. The
filtrate was washed with brine, dried with MgSO4, and evaporated in vacuo. Purification by
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