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Organic & Biomolecular Chemistry
(m, 6 H), 6.12 (m, 6 H), 6.89 (d, J = 8.7 Hz, 3 H), 7.25 (d, J = 139.7, 149.7, 159.0; HR-MS (ESI): found m/z = 591.3647
9.1 Hz, 3 H); 13C NMR (150.90 MHz, CDCl3): δ = 13.8, 27.4, (C33H53BO5SiNa), calculated m/z = 591.3654.
29.7, 32.4, 32.5, 33.6, 38.9, 41.0, 51.6, 55.3, 71.8, 73.1,
Bis-TBS ether 41. The following process was executed in the
74.4, 113.8, 128.6, 129.3, 129.7, 129.9, 130.1, 130.5, 130.7, dark and conducted in an amber glass septum vial. The iodide
131.6, 132.0, 132.4, 133.3, 133.9, 133.9, 134.1, 159.3, 173.4; 9 (6.43 mg, 13.5 μmol, 1.00 equiv.) and the pinacol borane 42
HR-MS (ESI): found m/z = 547.3047 (C32H4406Na), calculated (10.0 mg, 18.9 μmol, 1.4 equiv.) were diluted in anhydrous
m/z = 547.3030.
DMF (50 μL). Pd(dppf)Cl2 (2.96 mg, 1.60 μmol, 30 mol%) and
Pinacolborane 40. The following process was executed in the Ba(OH)2·8H2O (12.7 mg, 40.5 μmol, 3.0 equiv.) were added to
dark. Pd(CH3CN)2Cl2 (1.00 mg, 3.78 μmol, 5.0 mol%) was the vigorous stirring solution sequentially. The reaction
added to a solution of the iodide 9 (35.1 mg, 75.6 μmol, 1.0 mixture was stirred for 4 h. For purification diethyl ether
equiv.) and the stannane 5 (56.1 mg, 113 μmol, 1.5 equiv.) in (6 mL) and water (10 mL) were added to the reaction mixture.
degassed, anhydrous DMF (300 μL) in an amber glass septum After separation of the organic phase the aqueous phase was
vial. After stirring for 4 h the reaction mixture was diluted with extracted with diethyl ether (3 × 10 mL). The combined
3 mL of diethyl ether and washed with a saturated aqueous sol- organic layers were dried over MgSO4 and concentrated under
ution of NH4Cl (5 mL). The organic phase was separated and reduced pressure. After purification by column chromato-
the aqueous phase was extracted with diethyl ether (3 × 5 mL). graphy (SiO2, petroleum ether–ethyl acetate, 40 : 1) the product
The combined organic layers were dried over MgSO4, filtered 41 (8.40 mg, 11.2 μmol, 83%) was obtained as a clear, slightly
and concentrated under reduced pressure. Purification by yellow liquid. Rf = 0.40 (petroleum ether–ethyl acetate, 10 : 1);
1
column chromatography (SiO2, petroleum ether–ethyl acetate, [α]2D2 = +32.7 (c = 1.17, CHCl3); H NMR (600.130 MHz, CDCl3):
40 : 1–20 : 1) afforded the product 40 (36.5 mg, 67.3 μmol, 89%) δ = −0.04 (s, 3 H), 0.00 (s, 3 H), 0.01 (s, 3 H), 0.02 (s, 3 H), 0.86
as a slightly yellow liquid. Rf = 0.24 (petroleum ether–ethyl (s, 9 H), 0.88 (m, 12 H), 1.62 (s, 3 H), 1.79 (s, 3 H), 1.91 (m, 1
acetate, 20 : 1); 1H NMR (300.132 MHz, CDCl3): δ = −0.01 (br. s, H), 2.20 (m, 1 H), 2.32 (m, 3 H), 2.43 (m, 2 H), 3.35 (dd, J = 8.7
3 H), 0.01 (br. s, 3 H), 0.86 (s, 9 H), 1.28 (s, 12 H), 1.62 (br. s, 3 Hz, J = 6.3 Hz, 1 H), 3.43 (dd, J = 8.9 Hz, J = 5.6 Hz, 1 H), 3.67
H), 2.27 (m, 6 H), 3.67 (s, 3 H), 4.35 (m, 1 H), 5.16 (d, J = 7.4 (s, 3 H), 3.81 (s, 3 H), 4.34 (dd, J = 14.4 Hz, J = 6.6 Hz, 1 H),
Hz, 1 H), 5.57 (m, 1 H), 5.71 (td, J = 15.0 Hz, J = 7.5 Hz, 1 H), 4.40 (m, 2 H), 4.47 (dd, J = 9.0 Hz, J = 6.7 Hz, 1 H), 5.17 (m, 1
6.30 (m, 8 H), 7.05 (dd, J = 17.4 Hz, J = 10.3 Hz, 1 H); 13C NMR H), 5.44 (m, 1 H), 5.68 (m, 1 H), 6.11 (dd, J = 14.7 Hz, J =
(75.48 MHz, CDCl3): δ = −4.8, −4.3, 16.6, 18.2, 24.8, 25.8, 29.7, 9.5 Hz, 1 H), 6.20 (m, 1 H), 6.31 (m, 7 H), 6.88 (d, J = 8.5 Hz,
32.7, 34.3, 42.1, 51.6, 69.7, 83.2, 129.5, 130.9, 131.9, 132.4, 2 H), 7.26 (d, J = 8.5 Hz, 2 H); 13C NMR (150.90 MHz, CDCl3): δ
132.6, 133.3, 134.0, 134.5, 135.5, 136.7, 149.7, 173.6; HR-MS = −5.0, −4.8, −4.3, −4.2, 13.0, 13.0, 16.7, 18.1, 18.2, 25.8, 32.6,
(ESI): found m/z = 565.3498 (C31H51B05SiNa), calculated m/z = 34.3, 40.9, 42.1, 51.6, 55.3, 69.7, 70.7, 72.0, 72.6, 113.7, 128.1,
565.3497.
129.1, 129.4, 130.9, 131.3, 131.6, 132.6, 132.7, 132.8, 133.0,
Pinacolborane 42. The following process was executed in the 133.1, 133.2, 133.2, 133.9, 135.1, 137.5, 159.0, 173.6; HR-MS
dark. Pd(CH3CN)2Cl2 (2.70 mg, 10.3 μmol, 5.0 mol%) was (ESI): found m/z = 801.4923 (C46H7406Si2Na), calculated m/z =
added to a solution of the iodide 7 (100 mg, 204 μmol, 1.0 801.4916.
equiv.) and the stannane 5 (151 mg, 306 μmol, 1.5 equiv.) in
Diol 3. The following process was executed in the dark and
degassed, anhydrous DMF (2 mL) in an amber glass septum conducted in an amber glass septum vial. To a stirred solution
vial. After stirring for 12 h the reaction mixture was diluted of TBS ether 41 (19.4 mg, 24.9 μmol, 1.0 equiv.) in dry THF
with 10 mL of diethyl ether and washed with a saturated (1.5 mL) was added TBAF (124 μL, 1 M in THF, 124 μmol, 5.0
aqueous solution of NH4Cl (20 mL). The organic phase was equiv.). After stirring the reaction overnight CaCO3 (24.9 mg,
separated and the aqueous phase was extracted with diethyl 249 μmol, 10 equiv.), DOWEX 50WX8-200 (74.7 mg) and
ether (3 × 10 mL). The combined organic layers were dried methanol (300 μL) were added and the resulting suspension
over MgSO4, filtered and concentrated under reduced pressure. was stirred at room temperature for 1 h. All insoluble materials
Purification by column chromatography (SiO2, petroleum were removed by filtration through a short pad of silica gel.
ether–ethyl acetate, 30 : 1) afforded the product 42 (77.3 mg, The filter cake was washed with Et2O thoroughly and the com-
136 μmol, 67%) as an orange oil. Rf = 0.12 (petroleum ether– bined filtrates were concentrated in vacuo. Purification of the
ethyl acetate, 30 : 1); [α]2D2 = +12.1 (c = 1.13, CHCl3); 1H NMR crude product by preparative TLC (SiO2, petroleum ether–ethyl
(300.132 MHz, CDCl3): δ = −0.03 (s, 3 H), 0.01 (s, 3 H), 0.86 (s, acetate, 1 : 1) afforded diol 3 (8.00 mg, 14.5 μmol, 58%) as a
9 H), 0.88 (d, J = 4.1 Hz, 3 H), 1.29 (s, 12 H), 1.79 (s, 3 H), 1.93 shiny orange, oily liquid. Rf = 0.22 (petroleum ether–ethyl
(m, 1 H), 3.35 (dd, J = 8.9 Hz, J = 6.3 Hz, 1 H), 3.43 (dd, J = 9.1 acetate, 1 : 1); [α]2D2 = −1.00 (c = 0.61, CHCl3); 1H NMR
Hz, J = 5.6 Hz, 1 H), 3.81 (s, 3 H), 4.40 (m, 2 H), 4.48 (dd, J = (600.130 MHz, CDCl3): δ = 0.83 (d, J = 7.0 Hz, 3 H), 1.70 (s,
9.2 Hz, J = 6.5 Hz, 1 H), 5.48 (d, J = 9.2 Hz, 1 H), 5.56 (d, J = 3 H), 1.82 (s, 3 H), 1.94 (m, 1 H), 2.33 (m, 4 H), 2.45 (m, 2 H),
17.6 Hz, 1 H), 6.34 (m, 4 H), 6.88 (d, J = 8.5 Hz, 2 H), 7.07 (dd, 3.46 (t, J = 8.5 Hz, 1 H), 3.59 (dd, J = 9.2 Hz, J = 4.0 Hz, 1 H),
J = 17.6 Hz, J = 10.0 Hz, 1 H), 7.25 (d, J = 9.6 Hz, 2 H); 13C NMR 3.67 (s, 3 H), 3.81 (s, 3 H), 4.41 (m, 2 H), 4.47 (s, 2 H), 5.22 (d,
(75.48 MHz, CDCl3): δ = −5.0, −4.2, 12.9, 13.0, 13.6, 17.5, J = 8.6 Hz, 1 H), 5.48 (d, J = 8.9 Hz, 1 H), 5.68 (m, 1 H), 6.25 (m,
18.1, 24.8, 25.8, 26.8, 27.8, 40.9, 55.3, 70.7, 72.0, 72.6, 8 H), 6.89 (d, J = 8.4 Hz, 2 H), 7.26 (d, J = 8.4 Hz, 2 H);
83.2, 113.7, 127.5, 129.1, 130.9, 133.7, 134.0, 136.1, 136.9, 13C NMR (150.90 MHz, CDCl3): δ = 13.0, 13.4, 16.7, 32.5, 34.3,
2138 | Org. Biomol. Chem., 2013, 11, 2116–2139
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