Page 17 of 19
The Journal of Organic Chemistry
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2H), 3.30 (dd, J = 5.3, 1.0 Hz, 1H), 2.40 (s, 3H), 2.32__2.19 (m, 1H), 2.07__1.81 (m, 3H), 1.51__1.41 (m,
2H), 1.35__1.25 (m, 4H), 0.92__0.72 (m, 36H), 0.07__-0.11 (m, 24H); 13C NMR (100 MHz, CDCl3) δ 144.4,
133.5, 133.3, 129.7, 128.5, 127.9, 77.6, 70.9, 68.5, 66.9, 63.1, 32.8, 32.2, 29.5, 28.2, 26.0, 26.0, 25.8,
25.8, 25.8, 21.6, 18.4, 18.0, 17.8, -3.7, -4.0, -4.1, -4.2, -4.8, -5.1, -5.3; HRMS [DART+] (m/z): [M-
OTBS]+ Calcd for C37H71O6S1Si3 727.4279, Found 727.4296.
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(5R,6S,7S,8Z)-6,7-Bis((tert-butyldimethylsilyl)oxy)-2,2,3,3,16,16,17,17-octamethyl-5-octyl-4,15-
dioxa-3,16-disilaoctadec-8-ene (34). To a stirred solution of 33 (0.3 g, 0.35 mmol) in THF (25 mL) under
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Ar atmosphere at 0 C was added copper iodide (0.006 g, 0.035 mmol), hexylmagnesium bromide (2M
in diethyl ether, 0.70 mmol) and the reaction mixture was stirred for 1 h at the same temperature. After
completion of reaction monitored by TLC, sat. ammonium chloride and sat. sodium chloride solutions
were added and the mixture was extracted with ethyl acetate (30 mL x 2). The combined organic layers
were dried over sodium sulfate, and concentrated, then crude was purified by silica-gel flash column
chromatography using a mixture of 0.5% ethyl acetate and hexane as an eluent to afford 34 (0.186 g,
69%) as a colorless oil. Rf = 0.5 (2% ethyl acetate and hexane); [α]30D +12.0 (c 0.25, CHCl3); IR (neat):
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νmax (cm-1) 2953, 2927, 2891, 2854, 1469, 1384, 1252, 1101, 1005, 936, 832, 772; H NMR (400 MHz,
CDCl3) δ 5.43 (dd, J = 11.1, 9.3 Hz, 1H), 5.19 (dt, J = 11.2, 7.1 Hz, 1H), 4.71 (d, J = 9.0 Hz, 1H), 3.55 (t,
J = 6.6 Hz, 2H), 3.48 (ddd, J = 9.2, 4.9, 2.1 Hz, 1H), 3.29 (dd, J = 5.1, 1.7 Hz, 1H), 2.08__1.89 (m, 2H),
1.84__1.72 (m, 1H), 1.49__1.42 (m, 3H), 1.32__1.16 (m, 15H), 1.11__1.02 (m, 1H), 0.87__0.81 (m, 39H),
0.03__-0.05 (m, 24H); 13C NMR (100 MHz, CDCl3) δ 133.7, 128.1, 78.2, 77.2, 75.7, 67.1, 63.2, 32.9, 32.1,
31.9, 29.9, 29.6, 29.6, 29.3, 28.2, 27.7, 26.1, 26.0, 26.0, 25.9, 25.9, 25.8, 22.7, 18.4, 18.1, 18.1, 18.0, 14.1,
1.0, -0.0, -3.6, -3.8, -4.2, -4.3, -4.6, -4.6, -5.3; HRMS [DART+] (m/z): [M-OTBS]+ Calcd for C36H77O3Si3
641.5181, Found 641.5189.
(8S,9S,10R,6Z)-8,9,10-Tris((tert-butyldimethylsilyl)oxy)octadec-6-en-1-ol (35). To a stirred solution
º
of 34 (0.15 g, 0.19 mmol) in 1:1 MeOH and DCM (8 mL) was added CSA (0.013 g, 0.058 mmol) at 0
C, the mixture was stirred at the same temperature for 1 h. The reaction mixture was quenched with sat.
sodium bicarbonate solution, then extracted with DCM (15 mL x 2). The combined organic layers were
dried over sodium sulfate, concentrated, then crude was purified by column chromatography using 0.5%
ethyl acetate and hexane as an eluent gave recovered 34 (0.064g), and 35 (0.061 g, 83% based on
recovered starting material) as a colorless oil. Rf = 0.3 (2% ethyl acetate and hexane); [α] D28 +16.0 (c 0.3,
CHCl3); IR (neat): νmax (cm-1) 2954, 2927, 2855, 1471, 1254, 1080, 834, 805, 773; 1H NMR (400 MHz,
CDCl3) δ 5.46__5.38 (m, 1H), 5.18 (dt, J = 11.1, 7.2 Hz, 1H), 4.69 (d, J = 9.1 Hz, 1H), 3.64__3.54 (m, 2H),
3.50__3.43 (m, 1H), 3.28 (d, J = 5.0 Hz, 1H), 2.09__1.88 (m, 2H), 1.82__1.71 (m, 1H), 1.54__1.50 (m, 2H),
1.47__1.28 (m, 6H), 1.27__1.09 (m, 12H), 1.05__0.92 (m, 1H), 0.89__0.76 (m, 29H), -0.02__-0.08 (m, 18H);
13C NMR (100 MHz, CDCl3) δ 132.8, 126.9, 77.2, 76.2, 74.7, 66.0, 62.0, 31.7, 31.1, 30.9, 28.9, 28.6,
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