Â
V. Cõrkva et al. / Journal of Fluorine Chemistry 102 (2000) 159±168
166
the crude product was distilled to afford pure colorless
product (for reaction amounts, conversion, yields, product
purity and b.p (m.p.), see Table 1).
amounts, conversion, yields, product purity and b.p.
(m.p.), see Table 1).
2,2-Dimethyl-4-(3,3,4,4,5,5,6,6,6-nona¯uorohexyl)-1,3-
dioxolane (5a). Analysis: Found: C, 37.91; H, 3.86; F,
49.27%. C11H13F9O2 requires: C, 37.94; H, 3.76; F,
49.10%. M, 348.21. Summarized NMR spectra of 5a±c:
1H NMR (CDCl3) d: 1.36, 1.43 (2 Â s, 6H, 2CH3); 1.83 (m,
2H, CH2CHO); 2.23 (m, 2H, CH2CF2); 3.60 (dd, 1H(a),
2-(3,3,4,4,5,5,6,6,7,7,8,8,8-Trideca¯uorooctyl)oxolane
(2). Analysis: Found: C, 34.69; H, 2.74; F, 58.14%.
C12H11F13O1 requires: C, 34.46; H, 2.65; F, 59.06%. M,
418.20. 1H NMR (CDC13) d: 1.51 (ddt, 1H(a), CH2CH2CF2,
3
2JHH 11, JHH 9 and 7(t)); 1.79 (ddt, 1H(b),
2
3
2
3
CH2CH2CF2, JHH 11, JHH 7 and 4(t)); 1.91 (m,
2H, CH2CH2O); 2.03 (m, 2H, CH2CHO); 2.31 (m, 2H,
CH2CF2); 3.75, 3.85 (2 Â m, 2H, CH2O); 3.87 (m, 1H,
CHO) ppm. 19F NMR (CDC13) d: 81.38 (t, 3F, CF3,
3JFF 10); 115.02 (m, 2F, CF2CH2); 122.48 (m, 2F,
CF2CF2CH2); 123.41 (m, 2F, CF2(CF2)2CH2); 124.02
(m, 2F, CF2(CF2)3CH2); 126.71 (m, 2F, CF2CF3) ppm.
CH2O, JHH 6, JHH 8); 4.09 (t, 1H(b), CH2O,
2JHH JHH 6); 4.13 (ddt, 1H, CHO, JHH 12, 8 and
3 3
6(t)) ppm. 19F NMR (CDCl3) see (3a±c).
2,2-Dimethyl-4-(3,3,4,4,5,5,6,6,7,7,8,8,8-trideca¯uor-
ooctyl)-1,3-dioxolane (5b). Analysis: Found: C, 34.94; H,
3.06; F, 55.29%. C13H13F13O2 requires: C, 34.84; H, 2.92; F,
55.10%. M, 448.22.
5,5,6,6,7,7,8,8,8-Nona¯uoro-2-methyloctan-2-ol
(3a).
2,2-Dimethyl-4-(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-
heptadeca¯uorodecyl)-1,3-dioxolane (5c). Analysis: Found:
C, 33.07; H, 2.46; F, 59.34%. C15H13F17O2 requires: C,
32.86; H, 2.39; F, 58.91%. M, 548.24.
Analysis: Found: C, 35.47; H, 3.66; F, 56.66%.
C9H11F9O requires: C, 35.31; H, 3.62; F, 55.85%. M,
306.17. Summarized NMR spectra of 3a±c: 1H NMR
(CDCI3) d: 1.28 (s, 6H, 2CH3); 1.38 (bs, 1H, OH); 1.74
(m, 2H, CH2); 2.21 (m, 2H, CH2CF2) ppm. 19F NMR
4-(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-Heptadeca¯uoro-
decyl)-2,2,4-trimethyl-1,3-dioxolane
(18)
and
4-
3
(CDCl3) d: 81.37 to ±81.60 (t, 3F, CF3, JFF 10);
(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-Heptadeca¯uorodecyl)-
2,2,5-trimethyl-1,3-dioxolane (19). Analysis (18 19):
Found: C, 34.12; H, 2.84; F, 57.95%. C16H15F17O2 requires:
C, 34.18; H, 2.69; F, 57.44%. M, 562.27. 1H NMR (18, 84%
rel., CDCl3) d: 1.31, 1.39 (2 Â s, 9H, 3CH3); 1.74, 1.89
114.74 to
115.15 (m, 2F, CF2CH2);
122.20 to
124.87 (m, 2±10 F, 1±5 CF2); 126.48 to 126.75 (m,
2F, CF2CF3) ppm.
5,5,6,6,7,7,8,8,9,9,10,10,10-Trideca¯uoro-2-methylde-
can-2-ol (3b). Analysis: Found: C, 32.60; H, 2.74; F,
60.67%. C11H11F13O requires: C, 32.53; H, 2.73; F,
60.80%. M, 406.19.
5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-Heptadeca-
¯uoro-2-methyldodecan-2-ol (3c). Analysis: Found: C,
30.78; H, 2.23; F, 63.87%. C13H11F17O requires: C,
30.85; H, 2.19; F, 63.80%. M, 506.20.
2
3
(2 Â dt, 2H, CH2CH(CH3), JHH 12, JHH 12 and 5);
2,22 (m, 2H, CH2CF2); 3.78, 3.82 (2 Â d, 2H, CH2O,
1
2JHH 9) ppm. H NMR (19, 16% rel., CDCl3); d: 1.27,
1.29, 1.34, 1.44 (4 Â s, 9H, 3CH3); 1.70±1.90 (m, 2H, CH2);
2.22 (m, 2H, CH2CF2); 2.76, 2.92 (2 Â m, 1H, CH3CHO);
3.53 (dt, 1H, CH2CHO, 3JHH 8(t) and 3) ppm. 19F NMR
(CDCl3): see 3a±c.
5,5,6,6,7,7,8,8,9,9,10,10,10-Trideca¯uorodecan-2-ol (4).
Analysis: Found: C, 30.81; H, 2.34; F, 62.42%. C10H9F13O1
requires: C, 30.63; H, 2.31; F, 62.98%. M, 392.16. 1H NMR
4.2.3. General procedure for hydrolysis of fluoroalkylated
dioxolanes (5a±c) to the corresponding diols (15a±c)
Apparatus. The reactions were carried out in a round-
bottomed ¯ask (25 ml) equipped with Dimroth re¯ux con-
denser, a drying tube (potassium hydroxide) and with a
magnetic spinbar.
3
(CDCl3) d: 1.26 (d, 3H, CH3, JHH 6:2); 1.67 (bs, 1H,
OH); 1.72 (m, 2H, CH2); 2.22 (m, 2H, CH2CF2); 3.87 (ddq,
3
1H, CH, JHH 8, 6.2(q) and 4) ppm. 19F NMR (CDCl3)
see 2.
Reaction. A mixture of ¯uoroalkylated dioxolane (5a±c,
0.02 mol), methanol (12.8 g, 0.40 mol) and concentrated
hydrochloric acid (0.5 g) was re¯uxed for 3 h while stirring
(the complete conversion of the dioxolane was checked by
19F NMR or TLC). Methanol was removed on a rotary
evaporator and toluene (ca. 50 ml) was then added to the
residue and the mixture was fractionated on a packed
column (15 cm, Berle saddles, heated jacket). After distil-
ling toluene off under atmospheric pressure, the residue was
then distilled in vacuo and the product (15a±c) was taken
as the last fraction (for yields, purity, b.p. and m.p., see
Table 3).
4.2.2. Thermal initiation with dibenzoyl peroxide
(products 5a±c, 18, 19)
A homogenous mixture of per¯uoroalkylethylene (1a±c,
0.02 mol), dioxolane (17, 0.1 mol) and dibenzoyl peroxide
(0.48 g, 2 mmol) was deaerated for 0.5 h at ca. 208C with
a stream of argon (inlet±outlet by two needles through the
septa) in a ¯ask (25 ml) equipped with a dry-ice cooled
spiral re¯ux condenser with a hydraulic seal (sulfuric acid).
The reaction mixture was re¯uxed for 4 h while stirring (96±
97% conversion of ole®ns, monitoring by GC) and passing
through a slight stream of nitrogen. The reaction mixture
was passed through a short column of silica gel (1 Â 1 cm),
excess of dioxolane was distilled off (column 5 cm packed
with Berle saddles), and the crude product was distilled in
vacuo to afford pure colorless product (for reaction
5,5,6,6,7,7,8,8,8-Nona¯uorooctane-1,2-diol (15a). Ana-
lysis: Found: C, 31.44; H, 3.02; F, 55.49%. C8H9F9O2
requires: C, 31.18; H, 2.94; F, 55.49%. M, 308.14. Sum-
1
marized NMR spectra of 15a±c: H NMR (DMSO-d6) d: