M. Kirihara et al.
Journal of Fluorine Chemistry 243 (2021) 109719
Table 10
Comparison of the fluorinated allylic alcohol (1n) vs the non-fluorinated allylic alcohol (4).
Entry
R
Time
Staring Material 1n or 4 (%)a
Enone 2n or 5 (%)a
α
,β-epoxyketone 3′n or 6 (%)a
1
2
CF3
27 min
0
0
89
0
CH3
4 h 32 min
83
17
a
Isolated yield.
4.15. 2,2,2-Trifluoro-1-[(2RS, 3SR)-3-phenyloxiranyl]ethenone-1,1-diol
4.21. Standard experimental procedure for the synthesis of 1,1,1-
trifluoromethylꢀ ,βꢀ epoxyketone hydrates
(3n) [22]
α
Colorless crystals, mp: 139–140 ºC (lit.130–140 ºC [22])
1H NMR (CDCl3) δ: 3.48 (1H, d, J = 1.4 Hz), 4.03 (1H, d, J = 1.4 Hz),
4.20–4.26 (2H, br), 7.29–7.41 (5H, m)
The 1,1,1-trifluoromethylꢀ α,βꢀ epoxyketone hydrates were synthe-
sized according to the same procedure for the oxidation of fluorine-
containing alcohols using NaOCl⋅5H2O catalyzed by TEMPO.
13C NMR (CDCl3) δ: 55.40, 60.43, 92.25 (q, J = 32.6 Hz), 121.76 (q, J
= 287.5 Hz), 125.74, 128.69, 128.95, 134.36.
4.22. 2,2,2-Trifluoro-1-[(2RS, 3SR)-3-(4-nitrophenyl)oxiranyl]ethane-
19F NMR (CDCl3) δ: -84.83 (s).
1,1-diol (3′s)
Pale yellow crystals. mp: 79-82 ℃
4.16. Standard experimental procedure for the oxidation of fluorine-
1H NMR (Acetone-d6) δ: 3.03 (1H, s), 3.46 (1H, d, J = 1.8 Hz), 4.27
(1H, d, J = 1.8 Hz), 6.40 (1H, brd, J = 6.4 Hz), 7.65 (2H, d, J = 9.0 Hz),
8.26 (2H, d, J = 9.0 Hz).
containing alcohols using NaOCl⋅5H2O catalyzed by TEMPO in CD3CN
Potassium hydrogen sulfate (6.7 mg, 0.05 mmol), TEMPO (1.7 mg,
13C NMR (Acetone-d6) δ: 53.79, 61.81, 91.73 (q, J = 31.6 Hz),
124.06 (q, J = 287.5 Hz), 124.36, 127.81, 144.53, 148.86.
19F NMR(Acetone-d6) δ: -83.65 (3F, s).
0.01 mmol), and 4-chlorobenzotrifluoride (134.5 μL, 1.00 mmol, as the
internal standard) were added to a stirred solution of a fluoroalkyl
alcohol (1) (1.00 mmol) in CD3CN (5 mL) at room temperature, and the
resulting mixture was cooled to 0 ºC. Sodium hypochlorite pentahydrate
(395 mg, 2.4 mmol) was then added to the reaction mixture and stirred
under the same conditions. Part of the reaction solution (0.4 mL) was
collected, the 19F NMR was measured, and the yield of 2 was calculated.
IR (neat) cmꢀ 1: 3445, 3084, 2990, 1605, 1525, 1346, 1165, 1116,
1036, 908, 849, 721, 514, 453
MS (EI) (m/z): 261 [(M--H2O)+]
HRMS (ESI) calcd for C10H6F3NO4Na [(M+Na--H2O) +], 284.0141,
found: 284.0138.
4.17. Trifluoroacetic acid (2o) [23]
4.23. 1-[(2RS, 3SR)-3-(4-Fluorophenyl)oxiranyl]-2,2,2-trifluoroethane-
1,1-diol (3′t) [22]
The 19F-NMR peaks of this sample were identical to those of com-
mercial reagents.
Colorless crystals. mp: 76–78 ℃ (lit. 79–81 ℃ [22]).
1H NMR (CDCl3) δ: 3.43 (1H, d, J = 1.60 Hz), 3.71 (1H, br), 3.91 (1H,
br), 3.99 (1H, d, J = 1.60 Hz), 7.05-7.12 (2H, m), 7.25-7.33(2H, m).
13C NMR (CDCl3,) δ: 55.03, 59.73, 90.83 (q, J = 33.1 Hz), 115.83 (d,
J = 21.1 Hz), 122.29 (q, J = 285.6 Hz), 127.65 (d, J = 8.5 Hz), 129.98
(d, J = 2.8 Hz), 163.20 (d, J = 248.2 Hz).
19F NMR (CD3CN) δ: -75.3~ -75.4 (br).
4.18. 2,2-3,3,4,4,4-Heptafluorobutylic acid (2p) [23]
The 19F-NMR peaks of this sample were identical to those of com-
mercial reagents.
19F NMR (CDCl3) δ: -84.81 (3F, s), -112.75-112.68 (1F, m).
19F NMR (CD3CN) δ: -62.22 (3F, t, J = 8.7 Hz).ꢀ 117.44 (2F, q, J =
8.7 Hz), -126.82 (2F, brs).
4.24. 1-[(2RS, 3SR)-3–(4-Bromophenyl)oxiranyl]-2,2,2-
trifluoroethane-1,1-diol (3′u) [22]
4.19. Ethyl trifluoroacetate (2q) [23]
Colorless crystals. mp: 76–78 ℃ (lit. 77–78 ℃ [22])
1H NMR (CDCl3) δ: 3.40 (1H, d, J = 1.8 Hz), 3.96 (1H, d, J= 1.8 Hz),
7.1 8 (2H, d, J = 8.4 Hz). 7.52 (2H, d, J = 8.4Hz).
13C NMR (CDCl3) δ: 54.95. 59.78, 90.80 (d, J = 32.9 Hz), 122.28 (q, J
= 286.6 Hz), 123.11, 127.43, 131.93, 133.39.
1
The H-, 13C- and 19F-NMR peaks of this sample were identical to
those of commercial reagent.
1H NMR (CD3CN) δ: 1.32 (3H, t, J = 8.0 Hz), 4.39 (2H, q, J = 7.2 Hz).
13C NMR (CD3CN) δ: 13.91, 65.58, 115.28 (q, J = 284.7 Hz), 157.92
(q, J = 41.2 Hz).
19F NMR(CDCl3) δ: -84.83 (s)
19F NMR (CD3CN) δ: -75.2 (s).
4.25. 1-[(2RS, 3SR)-3-Butyloxiranyl]-2,2,2-trifluoroethane-1,1-diol
(3′x)
4.20. 1,1,1,3,3,3-Hexafluoro-2,2-propanediol (2′r) [24]
Pale yellow oil.
The 19F-NMR peak of this sample was similar to that (measured in
CDCl3) reported in the literature. [24]
1H NMR (CDCl3) δ: 0.92 (3H, t, J = 5.2 Hz), 1.36–1.74 (6H, m), 3.05
(1H, td, J = 5.7, 2.2 Hz), 3.14 (1H, d, J = 2.2 Hz).
13C NMR (CDCl3) δ: 13.81, 22.26, 27.55, 30.50, 56.02, 56.61, 90.86
19F NMR (CD3CN) δ: -82.4 (s)
9