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C. Audouard et al. / Journal of Fluorine Chemistry 126 (2005) 611–623
3.2. Ether synthesis by aqueous method A: preparation
of 3-(20,20,20-trifluoroethoxy)-prop-1-ene (5a)
F = 34.0), 17.4; dF (282 MHz; CDCl3) ꢀ74.5 to ꢀ74.7 (m);
[HRMS EI, M) Found: 154.06049. Calc. for C6H9F3O
154.06005]; m/z (EI) 154 (65%, M+), 139 (100%, M+–CH3).
Trifluoroethanol (1.00 mol, 72.7 mL) was added slowly
to a solution of potassium hydroxide (1.10 mol, 73.0 g) in
water (80 ml) at 0 8C. The mixture was stirred for 1 h at
room temperature. Allyl bromide (1.05 mol, 91.8 mL) was
added slowly at room temperature. The mixture was stirred
overnight at 0 8C, then allowed to cool and the organic layer
was separated from the aqueous layer and distilled from
calcium hydride to afford ether 5a as a colourless liquid
(139.0 g, 99%); bp 78 8C, nmax(film)/cmꢀ1 1277s, 1154s,
989w; dH (300 MHz, CDCl3) 5.89 (1H, ddt, J = 17.2, 10.4,
5.7, HC=CH2), 5.35–5.25 (2H, m, HC=CH2), 4.13 (2H, d,
3.5. Preparation of 2-(20,20,20-trifluoroethoxy)-but-3-
ene (5d)
From trifluoroethanol (50 g, 0.5 mol), potassium hydro-
xide (46 mL of a 24 M aqueous solution, 1.1 mol), 3-chloro-
1-butene (47.5 g, 0.525 mol) heated at 40 8C for 5 days. The
usual work up and distillation afforded ether 5d as a
colourless liquid, (46.9 g, 61%, 100% by GC), bp 80 8C;
n
max(film)/cmꢀ1: 2984w, 2937w, 1276m, 1157m, 1133m,
1108m, 965m; dH (300 MHz; CDCl3) 5.72 (1H, ddd,
J = 17.4, 10.2, 7.5, HC=CH2), 5.27–5.19 (2H, m, HC=CH2),
4.08–3.97 (1H, m, OCH(CH3)), 3.89–3.72 (2H, m,
CH2CF3), 1.3 (3H, d, J = 6.6, CH3); dC (75 MHz; CDCl3)
3
J = 5.5, CH2CH=CH2), 3.80 (2H, q, JH–F = 8.5, CF3CH2);
dC (75 MHz, CDCl3) 133.1, 124.1 (q, 1JC–F = 279.2), 118.5,
73.0, 67.0 (q, 2JC–F = 33.9); dF (282 MHz, CDCl3) ꢀ74.3 (t,
3JF–H = 8.5); [HRMS (EI, M+) Found: 140.04488. Calc. for
C6H9OF3 140.04490]; m/z (EI) 140 (35%, M+), 83 (80, M–
C3H5O), 71 (64), 55 (100).
1
2
138.5, 124.1 (q, JC–F = 277.5), 117.5, 78.7, 65.3 (q, JC–
F = 33.7), 20.1; dF (282 MHz; CDCl3) ꢀ74.4 (t, 3JF–H = 8.5);
[HRMS (EI, M) Found: 154.06057. Calc. for C6H9F3O
154.06005]; m/z (EI) 154 (62%, M+), 139 (78%, M+–CH3).
3.3. 2-Methyl-3-(20,20,20-trifluoroethoxy)-prop-1-ene (5b)
3.6. Preparation of 4-(20,20,20-trifluoroethoxy)-1-
(benzyloxy)-but-2Z-ene (5f)
From trifluoroethanol (200 mmol, 14.7 mL), potassium
hydroxide (220 mmol, 14.5 g), water (20 mL), methallyl
chloride (210 mmol, 20.7 mL) for 48 h at 40 8C. The usual
work up and distillation afforded ether 5b (20.0 g, 78%,
100% by GC); bp 92 8C, nmax(film)/cmꢀ1 3022w, 2944w,
1277s, 1156s, 989w; dH (300 MHz, CDCl3) 5.12–5.08 (2H,
m, (CH3)C=CH2), 4.15 (2H, s, =C(CH3)CH2), 3.88 (2H, q,
3JH–F = 8.9, CF3CH2), 1.86 (3H, s, CH3); dC (75 MHz,
From trifluoroethanol (3.99 g, 40 mmol), potassium
hydroxide (4.32 g, 77 mmol) in water (18 mL) and 1-
(benzyloxy)-4-chloro-2Z-butene 10 [22,23] (5.23 g,
27 mmol) at 85 8C for 24 h. The usual work up and
distillation (Kugelrohr) afforded ether 5f as a colourless
liquid (5.6 g, 81%, 100% by GC); bp 70 8C/0.04 mmHg, Rf
(5% diethyl ether in light petroleum ether) 0.35; nmax(film)/
cmꢀ1: 3032s, 2929m, 1496s, 1454s, 736s, 697s; dH
(300 MHz; CDCl3) 7.38–7.35 (5H, m, C6H5), 5.93–5.83
(1H, m, HC=CH), 5.78–5.68 (1H, m, HC=CH), 4.53 (2H, s,
PhCH2O), 4.20 (2H, d, J = 6.3, OCH2CH=), 4.10 (2H, d,
J = 6.6, OCH2CH=), 3.79 (2H, q, 3JH–F = 8.8, CF3CH2); dC
(75 MHz; CDCl3) 138.1, 131.0 (two signals), 128.5, 127.9
2
CDCl3) 141.1, 114.2, 76.4, 67.1 (q, JC–F = 34.0), 19.4; dF
(282 MHz, CDCl3) ꢀ74.8 (t, 3JF–H = 8.9); [HRMS (EI, M+)
Found: 154.06057. Calc. for C6H9OF3 154.06055]; m/z (EI)
154 (38%, M+), 139 (66), 113 (9), 55 (100).
3.4. Preparation of 4-(20,20,20-trifluoroethoxy)-but-2E-ene
(5c)
1
(two signals), 124.1 (q, JC–F = 279.5), 72.5, 67.8, 67.3 (q,
3
2JC–F = 34.0), 65.6; dF (282 MHz; CDCl3) ꢀ74.0 (t, JF–
H = 8.8); [HRMS (ES+, M + Na+) Found: 283.0932. Calc.
for C13H15O2F3Na 283.0922]; m/z (ES+) 283 (100%,
M + Na+).
From trifluoroethanol (10.0 g, 0.1 mol), potassium
hydroxide (4.6 mL of a 24 M aqueous solution, 0.22 mol),
crotyl chloride (9.51 g, 0.105 mmol, 5:1 mixture of E- and
Z-diastereoisomers) at 40 8C overnight. The usual work-up
and distillation afforded ether 5c as a colourless liquid
3.7. Preparation of 4-(20,20,20-trifluoroethoxy)-but-2-
yne (5h)
(13.4 g, 87%, 100% by GC), bp 83 8C; nmax(film)/cmꢀ1
:
3022w, 2944w, 1276s, 1156s, 1105s, 962s, 666m; dH
(300 MHz; CDCl3) major diastereoisomer1 E 5.72–5.63
(1H, m, =CHCH3), 5.52–5.42 (1H, m, CH=CHCH3), 4.06
From trifluoroethanol (3.4 g, 34 mmol), potassium
hydroxide (3.2 mL of a 24 M aqueous solution, 75 mmol),
4-chlorobut-2-yne (5 g, 37.6 mmol) heated at 40 8C for 18 h.
Usual work up and distillation afforded ether 5h as a
colourless liquid, (4.75 g, 92%, 100% by GC), bp 90 8C,
3
(2H, d, J = 6.3, OCH2CH), 3.70 (2H, q, JH–F = 8.5,
CF3CH2), 1.64 (3H, d, J = 6.3, CH3); dC (75 MHz; CDCl3)
1
2
131.9, 126.4, 124.1 (q, JC–F = 277.5), 73.2, 67.1 (q, JC–
n
1141s, 1109s, 1017m, 958m; dH (300 MHz; CDCl3) 4.25
max(film)/cmꢀ1: 2929w, 2864w, 2226w, 1277s, 1156s,
1
The following distinct peaks could be observed for the Z-diastereoi-
somer: dH (300 MHz; CDCl3) 4.20 (2H, d, J = 6.9, OCH2CH), 1.68 (3H, d,
3
(2H, d, 5J = 2.1, OCH2CBB ), 3.91 (2H, q, JH–F = 8.7,
2
J = 6.9, CH3); dC (75 MHz; CDCl3) 129.8, 125.1, 66.8 (q, JC–F = 33.7),
13.0. Other signals were indistinguishable from those from the E-isomer.
CF3CH2), 1.86 (3H, t, 5J = 2.1, BBCCH3); dC (75 MHz;