Synthesis and Comparison of the Reactivity of Allyl Fluorides and ...

195
Chapter Six
Hz, 4 JHF = 3.2 Hz, 2 JHH = 0.9 Hz, Ha), 5.84 (1H, ddt, 3 JHH = 17.2 Hz, 3 JHF = 12.6 Hz, 3 JHH =
10.8 Hz, Hc), 7.05 (2H, tm, 3 JHH = 8.8 Hz, ArH-3), 7.39 (2H, ddm, 3 JHH = 8.2 Hz, 4 JHF = 5.3
Hz, ArH-2); δC 76.7 (t, 2 JCF = 30.2 Hz, CHOH), 116.6 (d, 2 JCF = 22.6 Hz, ArCH-3), 120.9 (t,
1 JCF = 244.0 Hz, CF2), 123.3 (t, 3 JCF = 10.1 Hz, CHCH2), 130.5 (t, 2 JCF = 25.2 Hz, CHCH2),
130.8 (d, 3 JCF = 8.8 Hz, ArCH-2), 133.1 (ArC-1), 164.4 (d, 1 JCF = 247.7 Hz, ArCF); δF -
107.9 (d, 2 JFF = 249.1 Hz, CF), -109.6 (d, 2 JFF = 246.4 Hz, CF), -113.2 (1F, s, CF). m/z
(EI + ) 202 ([M] + , 14 %), 125 ([M-CF2CH=CH2] + , 100 %). HRMS (EI) 202.06045
(C10H9O1F3 requires 202.06032).
6.5.18 Preparation of 2,2-difluoro-1-(perfluorophenyl)but-3-en-1-ol (169)
The novel compound was prepared using a method
outlined by Audouard et al. [21] A 25 cm 3 round-bottomed
flask was set up in a sonicating bath, 3-bromo-3,3-
difluoroprop-1-ene (0.10 cm 3 , 0.98 mmol), 2,3,4,5,6-
pentafluoro- benzaldehyde (0.13 g, 0.66 mmol), indium
powder (0.11 g, 0.98 mmol) and water (7 cm 3 ) were added successively, and the reaction
mixture sonicated for 4 h at room temperature. After 4 h the reaction mixture was quenched
with HCl (20 cm 3 of a 1M aqueous solution), extracted with DCM and the combined
organic layers washed with brine (20 cm 3 ) and dried over magnesium sulphate. After
removal of solvent in vacuo the crude product was purified by column chromatography
[hexane: ethyl acetate (90:10)], affording the product as a solid (0.117 g, 65 %). δH 3.61
(1H, bd, 5 JHF = 9.1 Hz, OH), 5.24 (1H, ap.dt, 4 JHF = 14.0 Hz, 3 JHF = 8.5 Hz, CHOH), 5.60
(1H, dd, 3 JHH = 11.1 Hz, 2 JHH = 0.6 Hz, Hb), 5.75 (1H, ddt, 3 JHH = 17.2 Hz, 4 JHF = 3.2 Hz,
2 JHH = 0.9 Hz, Ha), 6.05 (1H, ddt, 3 JHH = 17.2 Hz, 3 JHF = 11.7 Hz, 3 JHH = 11.1 Hz, Hc); δC
68.4 (t, 2 JCF = 32.2 Hz, CHOH), 109.1 (tm, 2 JCF = 13.6 Hz, ArC-1) 117.6 (t, 1 JCF = 246.5 Hz,
CF2), 121.6 (t, 3 JCF = 9.1 Hz, CHCH2), 127.9 (t, 2 JCF = 25.2 Hz, CHCH2), 136.6 (dm, 1 JCF =
253.5 Hz, ArCF-3), 140.5 (dm, 1 JCF = 255.6 Hz, ArCF-4), 144.5 (dm, 1 JCF = 249.5 Hz,
ArCF-2) δF -108.2 (d, 2 JFF = 249.3 Hz, CF), -112.5 (d, 2 JFF = 249.3 Hz, CF), -140.7 (2F,dm
3 JFF = 21.8 Hz, ArF-2), -153.1 (1F, t, 3 JFF = 21.8 Hz, ArF-2), -161.9 (2F, m, ArF-3); m.p 51-
52 ºC.