was collected and the aqueous phase was extracted with hexanes.
The combined organic layers were washed thoroughly with water
and then once with brine. Drying (MgSO4) and evaporation of the
solvents left an oil which was purified by column chromatography
(silica gel 60, 10% ether in pentane) to give the title compound
(48 mg, 77% over 2 steps) as a colourless oil. dH(400 MHz; CDCl3;
Me4Si): 1.23 (t, 3H, J = 7.2 Hz), 1.68 (d, 3H, J = 6.4 Hz), 2.13–
2.28 (m, 4H), 4.13 (q, 2H, J = 7.2 Hz), 5.41–5.60 (m, 2H), 5.78 (dt,
1H, J = 1.6, 15.2 Hz), 5.91–6.02 (m, 2H), 6.90 (dt, 1H, J = 7.2,
15.2 Hz). dC(100 MHz; CDCl3; Me4Si): 14.1, 17.8, 30.8, 31.9, 59.9,
121.5, 127.5, 129.5, 131.2, 131.3, 148.1, 166.4. HRMS EI(m/z):
[M+] calcd. for C12H18O2, 194.1307; found, 194.1307.
water (5 ml), once aq. HCl (5 ml, 1M) and once more with water
(5 ml). The organic layer was dried (MgSO4) and the CH2Cl2
removed to give the crude aldehyde (26 mg), which was diluted
with tetrahydrofuran (0.5 ml) and used in the next step without
delay.
KOt-Bu (39 mg, 0.35 mmol) was added in one portion to a
stirred suspension of 1216 (165 mg, 0.4 mmol) in THF (3 ml) at
room temperature. Stirring was continued for a further 20 minutes
at this temperature, then the mixture was cooled to 0 ◦C and
the crude aldehyde solution was added in one portion. Stirring
was continued at 0 ◦C for 30 minutes, then saturated ammonium
chloride solution (7 ml) was then added and the organic phase was
separated. The aqueous phase was extracted into ether, and the
combine organic phases washed with brine, dried (MgSO4) and
concentrated in vacuo. Purification by column chromatography
(silica gel 60, 20% ethyl acetate in hexane) yielded the title
compound (19 mg, 40%) as a white solid. Mp = 104–106 ◦C.
dH(500 MHz; CDCl3; Me4Si): 0.92 (d, 6H, J = 6.8 Hz), 1.72 (d,
3H, J = 6.4 Hz), 1.79 (sept, 1H, J = 6.8 Hz), 2.15–2.27 (m, 4H),
3.16 (dd, 2H, J = 6.4, 6.4 Hz), 5.46–5.64 (m, 3H), 5.76 (d, 1H,
J = 15.2 Hz), 5.96–6.09 (m, 3H), 6.14 (dd, 1H, J = 10.4, 15.2 Hz),
7.17 (dd, 1H, J = 10.4, 15.2 Hz). dC(125 MHz; CDCl3; Me4Si):
18.0, 20.1, 28.6, 31.8, 32.8, 46.9, 122.1, 127.5, 128.6, 130.3, 131.1,
131.4, 141.1, 142.0, 166.3. Anal. Calcd: C, 77.68; H; 10.19; N, 5.66;
Found C 77.46; H, 10.18; N, 5.84%.
Deca-2(E),6(E),8(Z)-trienoic acid ethyl ester (10a). Prepared
in 71% yield from 9a utilizing the procedure used for synthesizing
10b. dH(300 MHz; CDCl3; Me4Si): 1.24 (t, 3H, J = 6.9 Hz), 1.69
(dd, 1H, J = 1.5, 6.9 Hz), 2.20–2.30 (m, 4H), 4.14 (q, 2H, J =
7.2 Hz), 5.36 (dq, 1H, J = 7.2, 10.8 Hz), 5.58 (dt, 1H, J = 6.3,
15.0 Hz), 5.80 (dt, 1H, J = 1.5, 15.6 Hz), 5.87–5.97 (m, 1H), 6.33
(dd, 1H, J = 10.8, 13.5 Hz), 6.92 (dt, 1H, J = 6.6, 15.6 Hz).
dC(100 MHz; CDCl3; Me4Si): 13.1, 14.1, 31.1, 31.9, 59.9, 121.7,
124.6, 126.3, 129.1, 131.9, 148.0, 166.4. HRMS EI(m/z): [M+]
calcd. for C12H18O2, 194.1307; found, 194.1306.
Deca-2(E),6(E),8(E)-trien-1-ol (11b). DIBAL (67 mg,
0.46 mmol) was dissolved in ether (6 ml) and the solution cooled
to 0 ◦C. Then 10b (45 mg, 0.23 mmol◦) dissolved in ether (2 ml) was
added dropwise. After stirring at 0 C for one hour, the mixture
was carefully quenched by the addition of water (0.2 ml), followed
by aq. HCl (3 ml, 1M). The mixture was stirred for 30 minutes,
then the organic layer was separated and the aqueous phase
extracted with ether. The combined ether layers were washed with
brine, dried (MgSO4) and evaporated. Purification of the residue
by column chromatography (silica gel 60, 20% ethyl acetate in
hexane) gave the title compound (28 mg, 82%) as a colourless
oil. dH(500 MHz; CDCl3; Me4Si): 1.71 (d, 3H, J = 6.5 Hz), 1.91
(s, 1H), 2.09–2.18 (m, 4H), 4.05 (d, 2H, J = 5 Hz), 5.47–5.70
(m, 4H), 5.95–6.03 (m, 2H). dC(125 MHz; CDCl3; Me4Si): 17.9,
31.9, 32.0, 63.5, 127.1, 129.3, 130.71, 130.74, 131.4, 132.2. HRMS
EI(m/z): [M+] calcd. for C10H16O, 152.1201; found, 152.1197.
Dodeca-2(E),4(E),8(E),10(Z)-tetraenoic acid isobutyl-amide (3).
Prepared in 43% yield as a white solid from 11a utilizing the
procedure used for synthesizing 4. Mp = 78–79 ◦C. dH(500 MHz;
CDCl3; Me4Si): 0.92 (d, 6H, J = 6.8 Hz), 1.73 (dd, 3H, J = 2.0,
6.8 Hz), 1.78 (sept, 1H, J = 6.8 Hz), 2.20–2.30 (m, 4H), 3.15
(dd, 2H, J = 6.8, 6.8 Hz), 5.39 (dq, 1H, J = 7.2, 10.8 Hz), 5.57–
5.66 (m, 2H), 5.77 (d, 1H, J = 14.8 Hz), 5.95 (dd, 1H, J = 11.0,
11.5 Hz), 6.05 (dt, 1H, J = 6.7, 14.8 Hz), 6.15 (dd, 1H, J = 10.8,
15.2 Hz), 6.34 (dd, 1H, J = 10.8, 15.2 Hz), 7.18 (dd, 1H, J = 10.4,
14.8 Hz). dC(125 MHz; CDCl3; Me4Si): 13.3, 20.1, 28.6, 32.1, 32.8,
46.9, 122.2, 124.6, 126.1, 128.7, 129.2, 132.6, 141.0, 141.8, 166.3.
Anal. Calcd: C, 77.68; H, 10.19; N, 5.66; Found C 77.36; H, 10.13;
N, 5.84%. MS (70 eV,%): m/z 247(M+ 2.4), 167(15.3), 152(3.6),
128(2.0), 115(10.4), 81(100), 79(44.7), 66(34.7), 57(31.9).
Deca-2(E),6(E),8(Z)-trien-1-ol (11a). Prepared in 87% yield
from 10a utilizing the procedure used for synthesizing 11b.
dH(500 MHz; CDCl3; Me4Si): 1.72 (dd, 3H, J = 1.5, 7.0 Hz),
1.90 (s, 1H), 2.10–2.22 (m, 4H), 4.06 (d, 2H, J = 4.5 Hz), 5.37
(dq, 1H, J = 7.0, 14.0 Hz), 5.60–5.71 (m, 3H), 5.95 (dt, 1H, J =
1.5, 11.6 Hz), 6.33 (ddq, 1H, J = 1.5, 11.0, 15.0 Hz). dC(125 MHz;
CDCl3; Me4Si): 13.2, 31.9, 32.3, 63.4, 124.3, 125.8, 129.2, 129.4,
132.1, 133.1. HRMS EI(m/z): [M+] calcd. for C10H16O, 152.1201;
found, 152.1201.
tert-Butyldimethyl((4E,6Z)-octa-4,6-dienyloxy)silane
(15).
Catechol borane (0.62 g, 5.2 mmol) and 13,22 (1.0 g, 5.07 mmol)
were mixed together at 60 ◦C for 4 hours, by which time 1H
NMR analysis indicated complete consumption of the alkyne
and formation of the (E)-benzodioxole alkenyl borane (14).
dH(300 MHz; CDCl3; Me4Si): 0.05 (s, 6H), 0.90 (s, 9H), 1.72
(pent, 2H, J = 6.6 Hz), 2.35 (br q, 2H, J = 6.6 Hz), 3.67 (t,
2H, J = 6.3 Hz), 5.80 (dt, 1H, J = 1.8, 18.3 Hz), 7.0–7.24 (m,
5H). A solution consisting of Pd(PPh3)4 (117 mg, 0.05 mmol)
and cis-1-bromopropene (0.605 g, 5.0 mmol) in benzene (8 ml)
was prepared, and the solution was stirred for 30 minutes at
25 ◦C. Then the alkenyl borane prepared above was added in
one portion followed by a solution of NaOEt in ethanol (5 ml,
2 M, 2 equivalents). The mixture was then stirred under reflux for
5 hours. After cooling to room temperature aq. NaOH (3 ml, 3M)
was added followed by aq. H2O2 (0.3 ml, 30%) and the mixture
was stirred at room temperature for 2 hours. Water (25 ml)
was then added and the mixture was extracted into ether (2 ×
15 ml). The combined ether layers were washed with brine, dried
Dodeca-2(E),4(E),8(E),10(E)-tetraenoic acid isobutyl-amide (4).
Oxalyl chloride (45 mg, 0.35 mmol) was added to CH2Cl2 (7.5 ml)
and the solution was cooled to −78 ◦C. DMSO (55 mg, 0.7 mmol)
was then added dropwise and after complete addition the solution
was stirred a further 2 minutes before the dropwise addition of
11b (30 mg, 0.2 mmol). Stirring was continued at −78 ◦C for
30 minutes and then the reaction was warmed to −10 ◦C for 5
◦
minutes. The mixture was cooled to −78 C and Et3N (354 mg,
3.5 mmol) was added slowly. After returning to room temperature,
the reaction was diluted with CH2Cl2 (8 ml), then washed once with
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