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D. Georgin et al. / Chemistry and Physics of Lipids 125 (2003) 83–91
type 3), 1.85 (q, J = 6.8 Hz, 2H, –CH2–CH2–Br),
2.05 (q, J = 7.3 Hz, 2H, proton type 1), 2.15–2.45
(m, 2H, proton type 4), 2.8 (t, J = 6.7, 2H, pro-
ton type 2), 2.95 (m, 2H, proton type 5), 3.40 (t,
J = 6.8 Hz, –CH2–Br), 5.25–5.55 (m, 4H, olefinic
H). MS (DCI/NH3): m/z (%): 349 (14), 348[M+ +18]
(87), 347 (24) 346[M+ + 18] (100), 331 (12), 329
(10), 313 (12), 311 (13), 123 (5).
1655(w), 1463(m), 1438(m), 1393(w), 1255(m),
1070(w), 967(m), 792(w), 723(m), 646(w), 564(w).
1H NMR(CDCl3): δ = 0.95 (t, J = 7.5 Hz, 3H,
–CH2–CH3), 1.2–1.45 (m, 8H), 1.85 (q, J = 7.1, 2H,
–CH2–CH2–Br), 1.9–2.10 (m, 4H, proton type 1),
2.70–2.85 (m, 4H, proton type 2), 3.40 (t, J = 6.8,
2H, –CH2–Br), 5.25–5.45 (m, 6H, olefinic H). MS
(DCI/NH3): m/z (%): 333 (25), 332[M+ + 18] (100),
331 (32), 330[M+ + 18] (100), 314[M+] (13), 313
(11), 312[M+] (15), 311 (6), 256 (16), 108 (21).
4.3. Erythro (3Z,6Z)-9,10,17-tribromoheptadeca-
3,6-diene
4.5. (9E,12Z,15Z)-[1-14C]-Octadeca-9,12,15-
trienenitrile
A mixture of 2-(7-bromoheptyl)-3-(2Z,5Z)-octa-2,
5-dienyl-oxirane (0.190 g, 0.58 mmol) in 5 ml of
toluene was added to triphenylphosphine dibro-
mide (0.244 g, 0.58 mmol) in 5 ml of toluene. The
mixture was vigorously stirred at room temper-
ature overnight, and the crude product was then
flash chromatographed on silica gel. The elution
with hexane–diethyl ether (99–1) afforded ery-
thro (3Z,6Z)-9,10,17-tribromo-heptadeca-3,6-diene
In a 25 ml-flask, 49 mg of (3Z,6Z,9E)-17-bromohe-
ptadeca-3,6,9-triene (0.15 mmol), 24 mg of 14C potas-
sium cyanide (55 mCi/mmol, 0.375 mmol, 20.6 mCi)
and 3 ml of dimethylsulphoxide were stirred for
20 min at 80 ◦C. Ten milliliter of water were added
and the aqueous layer was extracted three times with
20 ml diethyl ether. The mixture was dried under
vacuum and purified using flash chromatography
on silica gel with pentane–diethyl ether (95–5) as
eluant. The purified product was submitted to ra-
dioactive counting and mass spectrometry. 7.9 mCi
(55 mCi/mmol) (0.14 mmol) were obtained (96%
(0.178 g, 0.37 mmol, yield
=
64%). IR (film):
υ
=
3011 cm−1(m), 2931(s), 2857(s), 1458(m),
1433(m), 1217(w), 1148(w), 538(w) and 513(w).
1H NMR (CDCl3): δ = 0.95 (t, J = 7.5 Hz, 3H,
–CH2–CH3), 1.2–1.45 (m, 8H), 1.85 (q, J = 6.8, 2H,
–CH2–CH2–Br), 1.95–2.15 (m, 4H, protons type 1
and type 6), 2.70–2.85 (m, 4H, protons type 2 and
type7), 3.40 (t, J = 6.8 Hz, 2H, –CH2–Br), 5.25–5.5
(m, 6H, olefinic H + proton type 8). MS (DCI/NH3):
m/z (%): 494 (29), 493 (24), 492 (95), 491 (30), 490
(100), 489 (11), 488[M+ + 18] (32), 330 (20), 328
(12), 314 (21), 313 (92), 312 (28), 311 (95).
1
yield). H NMR(CDCl3): δ = 0.95 (t, J = 7.5 Hz,
3H, –CH2–CH3), 1.2–1.7 (m, 8H), 1.9–2.1 (m, 4H,
proton type 1), 2.35 (t, J = 7.1, 2H, –CH2–CN),
2.7–2.8 (m, 4H, proton type 2), 5.25–5.45 (m, 6H,
olefinic H). MS (DCI/NH3): m/z (%): 281 (6), 280
(33), 279[M+ + 18] (100), 278 (9), 277 (20).
4.6. (9E,12Z,15Z)-[1-14C]-Octadeca-9,12,15-
trienoic acid
4.4. (3Z,6Z,9E)-17-Bromoheptadeca-3,6,9-triene
A solution of erythro (3Z,6Z)-9,10,17-tribromohep-
tadeca-3,6-diene (0.109 g, 0.23 mmol) in N,N-dime-
thylformamide (2 ml) was added to an ice-cooled
slurry of activated zinc (0.109 mg), acetic acid (three
drops) and N,N-dimethylformamide (5 ml). Stirring
was continued at 0 ◦C for 2 h before the reaction
mixture was diluted with water and filtered. After ex-
traction with pentane and concentration in vacuum, a
flash chromatography on silica gel with pure heptane
afforded purified (3Z,6Z,9E)-17-bromoheptadeca-
3,6,9-triene (0.055 g, 0.17 mmol, yield = 76%). IR
(film): υ = 3012 cm−1(m), 2963(s), 2929(s), 2855(s),
In a 25 ml-flask, 7.9 mCi of (9E,12Z,15Z)-[1-14C]-
octadeca-9,12,15-trienenitrile: (0.14 mmol), 5 ml of
a 40% aqueous solution of potassium hydroxide
and 5 ml of absolute ethanol were stirred for 12 h at
85 ◦C. TLC control on silica gel with pentane–diethyl
ether–acetic acid (90–10–1) showed the end of the
reaction. The mixture was then acidified using 10 ml
5N hydrochloric acid and extracted with diethyl
ether. The purification by flash chromatography us-
ing the same system as the TLC afforded 6.85 mCi
of (9E,12Z,15Z)-[1-14C]-octadeca-9,12,15-trienoic
acid (55 mCi/mmol, 0.12 mmol, yield
=
89%).