ADDITION OF PERFLUOROALKANOIC ACIDS TO (R)-(+)-LIMONENE
549
1.4001. IR spectrum, ν, cm–1: 1769 (C=O); 1225, 1235
acetate). Yield 53%, bp 79–80°C (1 mm), nD20
=
1
1.3972. IR spectrum, ν, cm–1: 1772 (C=O); 1223, 1235
(CF3); 1125 (CF2). H NMR spectrum, δ, ppm: 1.33–
1
1.42 m (1H, 4-H), 1.55 s (6H, 9-H, 10-H), 1.65 s (3H,
7-H), 1.81–2.04 m (6H, 3-H, 5-H, 6-H), 5.37 s (1H,
(C–F). H NMR spectrum, δ, ppm: 1.34–1.44 m (4H,
3-H, 5-H), 1.53 s (6H, 9-H, 10-H), 1.58 s (3H, 7-H),
1.60–1.68 m (2H, 2-Hax, 6-Hax), 1.93 m (1H, 4-H),
2.42–2.47 m (2H, 2-Heq, 6-Heq). 13C NMR spectrum,
δC, ppm: 21.52 (C3, C5), 22.68 (C9, C10), 25.14 (C7),
35.35 (C2, C6), 45.82 (C4), 86.78 (C8), 91.10 (C1),
13
2-H). C NMR spectrum, δC, ppm: 22.41 (C10), 22.73
(C7), 22.98 (C9), 23.56 (C5), 26.07 (C3), 30.56 (C6),
43.04 (C4), 92.48 (C8), 119.65 (C2), 133.96 (C1),
1
104.32–111.74 m (CF2), 117.45 q.t (CF3, JCF = 288.1,
2
2JCF = 33.7 Hz), 157.76 t (C=O, JCF = 28.9 Hz).
1
114.4 q (CF3, JCF = 287.1 Hz), 156.0 q and 155.9 q
19F NMR spectrum, δF, ppm: –77.65 (CF3), –116.77
(CF2), –123.82 (CF2). Found, %: C 48.14; H 4.75.
C14H17F7O2. Calculated, %: C 48.01; H 4.89.
2
19
(C=O, JCF = 41.2 Hz). F NMR spectrum, δF, ppm:
–76.60, –76.56. Found, %: C 46.32; H 5.12.
C14H18F6O4. Calculated, %: C 46.16; H 4.98.
2-(4-Methylcyclohex-3-en-1-yl)propan-2-yl
heptadecafluorononanoate (IV, α-terpinyl per-
fluoropelargonate). A mixture of 2.5 g (18.3 mmol) of
(R)-(+)-limonene and 10.2 g (22.0 mmol) of perfluoro-
pelargonic acid in 10 ml of toluene was stirred for 6 h
at 30°C. The mixture was then washed with 0.1 N
aqueous KOH until neutral reaction and extracted with
diethyl ether (2×15 ml), the extract was dried over
MgSO4, and the solvent was distilled off under reduced
pressure. Yield 8.4 g (76%), yellow mobile liquid,
nD20 = 1.3716. IR spectrum, ν, cm–1: 1771 (C=O); 1224,
2-[4-(Heptafluorobutanoyloxy)-4-methylcyclo-
hexyl]propan-2-yl heptafluorobutanoate (VII,
terpin bis-perfluorobutyrate). Yield 68%, bp 104–
105°C (1 mm). IR spectrum, ν, cm–1: 1771 (C=O);
1
1224, 1236 (CF3); 1125, 1144 (CF2). H NMR spec-
trum, δ, ppm: 1.41–1.70 m (4H, 3-H, 5-H), 1.56 s (6H,
9-H, 10-H), 1.60 s (3H, 7-H), 1.91 m (1H, 4-H), 2.26–
13
2.51 m (4H, 2-H, 6-H). C NMR spectrum, δC, ppm:
21.48 (C9, C10), 22.68 (C3, C5), 25.24 (C7), 35.63 (C2,
C6), 45.32 (C4), 87.74 (C8), 91.87 (C1), 104.62–
1
2
1
128.93 m (CF2), 117.43 d.t (CF3, JCF = 287.5, JCF
=
1244 (CF3); 1153 (CF2). H NMR spectrum, δ, ppm:
33.7 Hz), 156.79 t and 156.68 t (C=O, 2JCF = 28.9 Hz).
19F NMR spectrum, δF, ppm: –81.82, –81.90 (CF3);
–119.89, –120.26 (CF2); –127.61, –127.94 (CF2).
Found, %: C 38.92; H 3.51. C18H18F14O4. Calculated,
%: C 38.31; H 3.22.
1.29–1.42 m (1H, 4-H), 1.53 s (3H, 10-H), 1.55 s (3H,
9-H), 1.65 s (3H, 7-H), 1.80–2.04 m (6H, 3-H, 5-H,
13
6-H), 5.37 s (1H, 2-H). C NMR spectrum, δC, ppm:
22.37 (C10), 22.69 (C7), 22.91 (C9), 23.55 (C5), 26.06
(C3), 30.52 (C6), 43.01 (C4), 92.57 (C8), 119.62 (C2),
133.98 (C1), 105.14–114.52 m (CF2), 117.07 q.t (CF3,
α-Terpinyl trifluoroacetate (I) from α-terpineol
and terpin bis-trifluoroacetate (V) from terpin
hydrate. A solution of 0.25–0.5 mol of trifluoroacetic
anhydride in 8–15 ml of carbon tetrachloride was
added dropwise under stirring and cooling to a solution
of 0.05 mol of terpin hydrate in 7 ml of carbon tetra-
chloride, maintaining the temperature not higher than
10°C. The mixture was then allowed to warm up to
room temperature and stirred for 0.5–1 h. The solvent,
excess trifluoroacetic anhydride, and trifluoroacetic
acid formed during the reaction were distilled off
under reduced pressure at a bath temperature not
exceeding 40°C, and the residue was subjected to
vacuum distillation.
2
2
1JCF = 288.1, JCF = 32.9 Hz), 156.90 t (C=O, JCF
=
19
28.9 Hz). F NMR spectrum, δF, ppm: –82.03 (CF3);
–119.33, –122.71, –123.06, –123.57, –123.90 (CF2).
Found, %: C 37.69; H 2.41. C19H17F17O2. Calculated,
%: C 38.01; H 2.85.
p-Menthane-1,8-diyl bis(perfluoroalkanoates) V
and VII (general procedure). A solution of 0.07 mol of
(R)-(+)-limonene in 20 ml of toluene was cooled to
0°C, 0.18 mol of trifluoroacetic or heptafluorobutanoic
acid was added dropwise under stirring, and a few
drops of concentrated (95%) sulfuric acid were then
added. The mixture was stirred for 45 min (in the
synthesis of V) or 2.5 h (in the synthesis of VII),
maintaining the temperature about 0°C. The mixture
was then allowed to warm up to room temperature and
treated in succession with 10 ml of water, 10 ml of 5%
aqueous NaHCO3, and 10 ml of 5% aqueous NaCl.
The organic phase was dried over MgSO4, the solvent
was distilled off under reduced pressure, and the
residue was purified by vacuum distillation.
α-Terpinyl trifluoroacetate (I). Yield 67%, bp 59–
61°C (1 mm), nD20 = 1.4215. The IR and H and 19F
1
NMR spectra of the product were fully identical to
those of a sample synthesized from limonene.
Terpin bis-trifluoroacetate (V). Yield 51%,
bp 80–81°C (1 mm), nD22 = 1.3955. The IR and H and
1
2-[4-Methyl-4-(trifluoroacetyloxy)cyclohexyl]-
propan-2-yl trifluoroacetate (V, terpin bis-trifluoro-
19F NMR spectra of the product were fully identical to
those of a sample synthesized from limonene.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 49 No. 4 2013