2164
B. Saikia et al. / Tetrahedron 69 (2013) 2157e2166
12.29%; Rf (30% EtOAc/Hexane) 0.55; ½a D25
ꢂ
ꢁ8.56 (c 0.82, CHCl3); IR
1H NMR
26b (0.186 g, 0.249 mmol, 93%) was a colourless gum; Elemental
nmax (KBr) 3423 (br), 2951, 2841, 1312, 1134 cmꢁ1
;
analysis calcd. Found: C, 68.89; H, 11.27; O, 8.50. C48H84O4Si3 re-
(300 MHz, CDCl3)
d
7.32e7.30 (5H, m, Aromatic), 5.75 (1H, dd,
quires C, 68.92; H, 11.30; O, 8.54%; Rf (10% EtOAc/Hexane) 0.84; ½a D25
ꢂ
J¼15.3, 6.5 Hz, 7CH), 5.70 (1H, dd, J¼15.3, 6.5 Hz, 8CH), 4.63 (2H, s,
OCH2Ph), 4.07 (1H, q, J¼6.5 Hz, 6H), 3.95 (1H, dd, J¼6.7, 4.4 Hz,
9CH), 3.60e3.58 (1H, m, 10CH), 3.53 (2H, t, J¼4.2 Hz, 1CH2), 2.01
(2H, br s, 2OH), 1.56e1.51 (8H, m, aliphatic chain), 1.40e1.25 (14H,
m, aliphatic chain),1.10 {9H, s, (CH3)3(CH3)2Si}, 0.94 (3H, t, J¼6.7 Hz,
18CH3), 0.09 {6H, s, (CH3)3(CH3)2Si}; 13C NMR (75 MHz, CDCl3)
þ17.5 (c 0.25, CHCl3); IR nmax (film) 2947, 2851, 1430, 1145,
1038 cmꢁ1; 1H NMR (300 MHz, CDCl3)
d 7.33e7.29 (5H, m, Aromatic),
5.89 (1H, dd, J¼15.6, 6.9 Hz, 7CH), 5.78 (1H, dd, J¼15.6, 6.9 Hz, 8CH),
4.63 (2H, s, OCH2Ph), 4.09 (1H, q, J¼6.5 Hz, 6CH), 3.95 (1H, dd, J¼6.7,
4.5 Hz, 9CH), 3.60e3.58 (1H, m, 10CH), 3.57 (2H, t, J¼7.3 Hz, 1CH2),
1.55e1.49 (8H, m, aliphatic chain), 1.32e1.26 (14H, m, aliphatic
chain), 1.0 {27H, s, 3(CH3)3(CH3)2Si}, 0.96 (3H, t, J¼6.7 Hz, 18CH3),
d
137.9, 132.1, 131.9, 128.4, 127.6, 127.4, 127.1, 84.1, 75.3, 75.2, 73.9,
66.3, 38.1, 34.9, 32.8, 32.4, 30.8, 30.6, 30.1, 27.1, 24.8, 24.2, 23.3, 20.7,
0.08 {18H, s, 3(CH3)3(CH3)2Si}; 13C NMR (75 MHz, CDCl3)
d 137.9,
15.1, 14.2, ꢁ6.2; MS (ESI, positive ion): m/z (%)¼520.8 (100) [Mþ].
131.9, 131.8, 128.6, 128.3, 128.1, 127.3, 127.1, 91.1, 74.5, 74.3, 74.1, 69.1,
40.2, 38.6, 35.2, 32.9, 30.8, 30.3, 30.1, 26.8, 24.4, 23.9, 20.7, 15.6,14.3,
ꢁ6.3; MS (ESI, positive ion): m/z (%)¼772.1 (100) [MþNa]þ.
4.25. 9-Benzyloxy-1-(tert-butyl-dimethyl-silanyloxy)-octa-
dec-7-ene-6,10-diol (25b)
4.28. 9-Benzyloxy-6,10-bis-(tert-butyl-dimethyl-silanyloxy)-
The synthetic procedure of compound 25b was same as that was
used for the synthesis of 25a. Compound 25b (0.144 g, 0.277 mmol,
78%) was a white solid; Elemental analysis calcd. Found: C, 71.38; H,
10.73; O, 12.20. C31H56O4Si requires C, 71.48; H, 10.84; O, 12.29%; Rf
octadec-7-en-1-ol (27a)
An ice-bath cooled solution of the tris-TBS ether 26a (0.400 g,
0.533 mmol) in MeOH (5 mL) was treated with p-TsOH (0.009 g,
0.052 mmol) as a solid. The reaction mixture was stirred at the
same temperature for 30 min. The reaction mixture was quenched
with solid NaHCO3 (3 g) and filtered. The filtrate was concentrated
under reduced pressure. The residue was purified by flash column
chromatography (7% EtOAc/Hexane) to afford 27a (0.324 g,
0.511 mmol, 96%) as a colourless gummy liquid; Elemental analysis
calcd. Found: C, 69.92; H, 11.10; O, 10.05. C37H70O4Si2 requires C,
(30% EtOAc/Hexane) 0.54; ½a D25
ꢂ
þ12.01 (c 0.54, CHCl3); IR nmax (KBr)
3434 (br), 2941, 2831, 1312, 1130 cmꢁ1
;
1H NMR (300 MHz, CDCl3)
d
7.33e7.25 (5H, m, Aromatic), 5.82 (1H, dd, J¼15.6, 7.0 Hz, 7CH),
5.76 (1H, dd, J¼15.6, 6.9 Hz, 8CH), 4.63 (2H, s, OCH2Ph), 4.08 (1H, q,
J¼6.7 Hz, 6H), 3.95 (1H, dd, J¼6.7, 4.2 Hz, 9CH), 3.61e3.58 (1H, m,
10CH), 3.53 (2H, t, J¼4.3 Hz, 1CH2), 2.01 (2H, br s, 2OH), 1.58e1.53
(8H, m, aliphatic chain), 1.41e1.34 (14H, m, aliphatic chain), 1.11
{9H, s, (CH3)3(CH3)2Si}, 0.94 (3H, t, J¼6.7 Hz, 18CH3), 0.09 {6H, s,
69.97; H, 11.11; O, 10.08%; Rf (40% EtOAc/Hexane) 0.45; ½a D25
ꢁ33.56
ꢂ
(CH3)3(CH3)2Si}; 13C NMR (75 MHz, CDCl3)
d
137.9, 132.2, 131.6,
(c 0.25, CHCl3); IR nmax (film) 3422 (br), 2941, 2833, 1642, 1440,
128.4, 127.7, 127.3, 127.0, 84.3, 75.3, 75.1, 73.9, 66.5, 37.9, 34.9, 32.8,
32.3, 30.6, 30.5, 30.1, 27.1, 24.8, 24.2, 23.4, 20.7, 15.1, 14.3, ꢁ6.2; MS
(ESI, positive ion): m/z (%)¼520.6 (100) [Mþ].
1142 cmꢁ1 1H NMR (300 MHz, CDCl3)
; d 7.31e7.27 (5H, m, Aro-
matic), 5.89 (1H, dd, J¼15.5, 6.5 Hz, 7CH), 5.79 (1H, dd, J¼15.5,
6.5 Hz, 8CH), 4.64 (2H, s, OCH2Ph), 4.07 (1H, q, J¼6.5 Hz, 6CH), 3.95
(1H, dd, J¼6.7, 4.4 Hz, 9CH), 3.60e3.58 (1H, m, 10CH), 3.53 (2H, t,
J¼7.3 Hz, 1CH2), 2.01 (1H, br s, OH), 1.55e1.50 (8H, m, aliphatic
chain), 1.39e1.25 (14H, m, aliphatic chain), 1.0 {18H,
s, 2(CH3)3(CH3)2Si}, 0.94 (3H, t, J¼6.7 Hz, 18CH3), 0.09 {12H,
4.26. [1-[3,8-Bis-(tert-butyl-dimethyl-silanyloxy)-oct-1-enyl]-
2-(tert-butyl-dimethyl-silanyloxy)-decyloxymethyl]-benzene
(26a)
s, 2(CH3)3(CH3)2Si}; 13C NMR (75 MHz, CDCl3)
d 137.8, 132.1, 131.9,
Diol 25a (0.330 g, 0.634 mmol) was dissolved in dry DCM (4 mL).
Imidazole (0.043 g, 0.634 mmol) and TBSCl (0.095 g, 0.634 mmol)
were added, and the mixture was stirred at room temperature for
4 h. After completion of the reaction the mixture was diluted with
Et2O (8 mL), the solution was washed with H2O (3ꢃ10 mL), dried
over anhydrous Na2SO4 and concentrated under reduced pressure.
The resulting residue was purified by column chromatography on
silica gel (2% EtOAc/Hexane) to give the compound 26a (0.451 g,
0.602 mmol, 95%) as colourless gum; Elemental analysis calcd.
Found: C, 68.90; H, 11.28; O, 8.51. C48H84O4Si3 requires C, 68.92; H,
128.9, 128.7, 127.6, 127.5, 127.2, 84.7, 74.3, 74.1, 73.6, 63.8, 40.1, 33.5,
33.2, 32.5, 30.3, 30.1, 26.7, 24.5, 24.2, 23.1, 20.7, 15.1, 14.7, ꢁ6.2; MS
(ESI, positive ion): m/z (%)¼635.1 (100) [Mþ].
4.29. 9-Benzyloxy-6,10-bis-(tert-butyl-dimethyl-silanyloxy)-
octadec-7-en-1-ol (27b)
The synthetic procedure of compound 27b was same as that was
used for the synthesis of 27a. Compound 27b (0.110 g, 0.174 mmol,
87%) was a colourless gum; Elemental analysis calcd. Found: C,
69.90; H, 11.0; O, 10.01. C37H70O4Si2 requires C, 69.97; H, 11.11; O,
11.30; O, 8.54%; Rf (10% EtOAc/Hexane) 0.85; ½a D25
ꢂ
ꢁ15.2 (c 0.12,
CHCl3); IR nmax (film) 2940, 2841, 1429, 1142, 1055 cmꢁ1
;
1H NMR
10.08%; Rf (40% EtOAc/Hexane) 0.45; ½a D25
ꢂ
þ23.71 (c 0.25, CHCl3); IR
(300 MHz, CDCl3)
d
7.31e7.29 (5H, m, Aromatic), 5.86 (1H, dd,
nmax (film) 3419 (br), 2947, 2812, 1638, 1441, 1143 cmꢁ1 1H NMR
;
J¼15.3, 6.5 Hz, 7CH), 5.76 (1H, dd, J¼15.3, 6.5 Hz, 8CH), 4.63 (2H, s,
OCH2Ph), 4.07 (1H, q, J¼6.5 Hz, 6CH), 3.95 (1H, dd, J¼6.7, 4.4 Hz,
9CH), 3.60e3.58 (1H, m, 10CH), 3.57 (2H, t, J¼7.3 Hz, 1CH2),
1.54e1.49 (8H, m, aliphatic chain), 1.32e1.25 (14H, m, aliphatic
chain), 1.0 {27H, s, 3(CH3)3(CH3)2Si}, 0.96 (3H, t, J¼6.7 Hz, 18CH3),
(300 MHz, CDCl3) d 7.33e7.29 (5H, m, Aromatic), 5.89 (1H, dd,
J¼15.5, 6.6 Hz, 7CH), 5.79 (1H, dd, J¼15.6, 6.6 Hz, 8CH), 4.64 (2H, s,
OCH2Ph), 4.08 (1H, q, J¼6.5 Hz, 6CH), 3.96 (1H, dd, J¼6.7, 4.4 Hz,
9CH), 3.60e3.59 (1H, m, 10CH), 3.54 (2H, t, J¼7.3 Hz, 1CH2), 2.0 (1H,
br s, OH), 1.55e1.49 (8H, m, aliphatic chain), 1.39e1.26 (14H, m, al-
iphatic chain), 1.0 {18H, s, 2(CH3)3(CH3)2Si}, 0.94 (3H, t, J¼6.7 Hz,
18CH3), 0.09 {12H, s, 2(CH3)3(CH3)2Si}; 13C NMR (75 MHz, CDCl3)
0.08 {18H, s, 3(CH3)3(CH3)2Si}; 13C NMR (75 MHz, CDCl3)
d 137.9,
131.9, 131.8, 128.9, 128.7, 128.6, 127.5, 127.2, 127.0, 91.0, 74.5, 74.3,
74.1, 69.1, 40.2, 38.6, 35.2, 32.9, 30.9, 30.3, 30.1, 26.8, 24.5, 23.7, 20.7,
15.6, 14.2, ꢁ6.3; MS (ESI, positive ion): m/z (%)¼749.3 (100) [Mþ].
d
137.8, 132.3, 131.2, 128.8, 128.5, 127.7, 127.5, 127.2, 84.5, 74.8, 74.7,
73.6, 64.0, 40.2, 33.3, 33.2, 32.4, 30.2, 30.1, 26.9, 24.4, 23.8, 23.1, 20.5,
15.2, 14.7, ꢁ6.2; MS (ESI, positive ion): m/z (%)¼635 (100) [Mþ].
4.27. [1-[3,8-Bis-(tert-butyl-dimethyl-silanyloxy)-oct-1-enyl]-
2-(tert-butyl-dimethyl-silanyloxy)-decyloxymethyl]-benzene
(26b)
4.30. 9-Benzyloxy-6,10-bis-(tert-butyl-dimethyl-silanyloxy)-
octadec-7-enoic acid (28a)
Compound 26b was prepared from 25b according to the same
procedure that was followed for the synthesis of 26a. Compound
Alcohol 27a (0.300 g, 0.472 mmol) was dissolved in CH2Cl2
(3 mL) and treated with the DMP (0.240 g, 0.566 mmol, 1.2 equiv).