S. Murakami et al. / Journal of Fluorine Chemistry 125 (2004) 609–614
613
(254 MHz, CDCl3) d: ꢂ26.65 (d, 2 F, J ¼ 9:4 Hz) MS (m/z)
226 (Mþ), 153, 91, 77. HRMS m/z calced for C12H12F2O2:
226.0805. Found: 226.0818.
1.36 (t, 3 H, J ¼ 7:3 Hz), 1.28 (s, 9 H) 19F NMR (254 MHz,
CDCl3) d: ꢂ18.40 (d, 2 F, J ¼ 9:4 Hz) MS (m/z) 222 (Mþ),
207, 149. HRMS m/z calced for C10H16F2O2: 222.1068.
Found: 222.1076.
3.4.6. Ethyl 2,2-difluoro-4-phenyl-3-pentanoate (5c)
1H NMR (270 MHz, CDCl3) d: 7.32–7.16 (m, 5 H), 4.09–
3.97 (m, 2 H), 3.13–3.00 (m, 1 H), 2.60–2.22 (m, 2 H), 1.34
(d, 3 H, J ¼ 7:0 Hz), 1.24 (t, 3 H, J ¼ 7:0 Hz) 19F NMR
(254 MHz, CDCl3) d: ꢂ24.63 (dt, 2 F, J ¼ 262:6, 16.5 Hz),
ꢂ29.88 (dt, 2 F, J ¼ 262:6, 16.5 Hz) MS (m/z) 242 (Mþ),
105, 77. HRMS m/z calced for C13H16F2O2: 242.1118.
Found: 242.1099.
3.4.13. 2H-3,4,5,6-Tetrahydro-3-
(ethoxycarbonyldifluoromethyl)pyran (5f)
1H NMR (270 MHz, CDCl3) d: 4.34 (q, 2H, J ¼ 7:0 Hz),
4.05–3.90 (m, 2H), 3.42–3.29 (m, 2H), 2.52–2.30 (m, 1H),
1.70–1.49 (m, 4H), 1.36 (t, 3H, J ¼ 7:0 Hz) 19F NMR
(254 MHz, CDCl3) d: ꢂ35.10 (dd, 1F, J ¼ 259:0,
14.7 Hz), ꢂ36.88 (dd, 1F, J ¼ 259:0, 14.7 Hz) MS (m/z)
208 (Mþ), 135. HRMS m/z calced for C9H14F2O3: 208.0911.
Found: 208.0905.
3.4.7. Ethyl 2,2-difluoro-4-phenyl-4-pentenoate (6c)
1H NMR (270 MHz, CDCl3) d: 7.39–7.25 (m, 5 H), 5.05
(d, 1 H, J ¼ 0:8 Hz), 5.31 (d, 1 H, J ¼ 0:8 Hz), 4.05 (q, 2 H,
J ¼ 7:0 Hz), 3.30 (td, 2 H, J ¼ 15:4, 0.8 Hz), 1.21 (t, 3 H,
J ¼ 7:0 Hz) 19F NMR (254 MHz, CDCl3) d: ꢂ26.83 (t, 2 F,
J ¼ 14:7 Hz) MS (m/z) 240 (Mþ), 195, 167, 103, 77. HRMS
m/z calced for C13H14F2O2: 240.0962. Found: 240.0950.
3.4.14. 2H-3,4-Dihydro-5-
(ethoxycarbonyldifluoromethyl)pyran (6f)
1H NMR (270 MHz, CDCl3) d: 6.86–6.83 (m, 1H), 4.33
(q, 2H, J ¼ 7:0 Hz), 4.01 (dd, 2H, J ¼ 5:1, 5.1 Hz), 2.14
(td, 2H, J ¼ 6:2, 1.4 Hz), 1.94–1.86 (m, 2H), 1.35 (t, 3H,
J ¼ 7:0 Hz) 19F NMR (254 MHz, CDCl3) d: ꢂ28.17 (s, 2F)
MS (m/z) 206 (Mþ), 133. HRMS m/z calced for C9H12F2O3:
206.0755. Found: 206.0750.
3.4.8. Ethyl 2,2-difluoro-4,4-diphenylbutanoate (5d)
1H NMR (270 MHz, CDCl3) d: 7.31–7.14 (m, 10 H), 4.27
(t, 1 H, J ¼ 7:0 Hz), 3.84 (q, 2 H, J ¼ 7:3 Hz), 2.93 (dt, 2 H,
J ¼ 7:3, 15.4 Hz), 1.16 (t, 3 H, J ¼ 7:3 Hz) 19F NMR
(254 MHz, CDCl3) d: ꢂ26.87 (t, 2 F, J ¼ 14:0 Hz) MS
(m/z) 304 (Mþ), 259, 167. HRMS m/z calced for
C18H18F2O2: 304.1275. Found: 304.1245.
3.4.15. Ethyl 2,2-difluoro-2-cyclohexyletanate (5g)
1H NMR (270 MHz, CDCl3) d: 4.32 (q, 2H, J ¼ 7:3 Hz),
2.17–1.96 (m, 1H), 1.83–1.68 (m, 5H), 1.35 (t, 3H,
J ¼ 7:3 Hz), 1.28–1.18 (m, 5H) 19F NMR (254 MHz,
CDCl3) d: ꢂ37.05 (d, 2F, J ¼ 14:7 Hz) MS (m/z) 206
(Mþ), 133. HRMS m/z calced for C10H16F2O2: 206.1118.
Found: 206.1133.
3.4.9. Ethyl 2,2-difluoro-4,4-diphenyl-3-butenoate (6d)
1H NMR (270 MHz, CDCl3) d: 7.51–7.18 (m, 10 H), 6.27
(t, 1 H, J ¼ 12:0 Hz), 3.90 (q, 2 H, J ¼ 7:0 Hz), 1.17 (t, 3 H,
J ¼ 7:0 Hz) 19F NMR (254 MHz, CDCl3) d: ꢂ14.38 (d, 2 F,
J ¼ 11:0 Hz) MS (m/z) 302 (Mþ), 229. HRMS m/z calced
for C18H16F2O2: 302.1118. Found: 302.1115.
3.4.16. Ethyl 2-(cyclohexen-1’-yl)-2,2-
difluoromethylacetate (6g)
1H NMR (270 MHz, CDCl3) d: 6.20–6.17 (m, 1 H), 4.33
(q, 2 H, J ¼ 7:0 Hz), 2.11–2.01 (m, 4 H), 1.71–1.54(m, 4 H),
1.35 (t, 3 H, J ¼ 7:0 Hz) 19F NMR (254 MHz, CDCl3) d:
ꢂ30.45 (s, 2 F) MS (m/z) 204 (Mþ), 131. HRMS m/z calced
for C10H14F2O2: 204.0962. Found: 204.0955.
3.4.10. Ethyl 5-t-butoxy-2,2-difluorobutanoate (5e)
1H NMR (270 MHz, CDCl3) d: 4.30 (q, 2 H, J ¼ 7:0 Hz),
3.52 (t, 2 H, J ¼ 6:2 Hz), 2.43–2.27 (m, 2 H), 1.35 (t, 3 H,
J ¼ 7:0 Hz), 1.15 (s, 9 H) 19F NMR (254 MHz, CDCl3) d:
ꢂ29.31 (t, 2 F, J ¼ 14:7 Hz) MS (m/z) 224 (Mþ), 167.
HRMS m/z calced for C10H18F2O2: 224.1224. Found:
224.1230.
3.4.17. Ethyl 2-(cyclohexen-2’-yl)-2,2-
difluoromethylacetate (6g0)
1H NMR (270 MHz, CDCl3) d: 5.98–5.93 (m, 1 H),
5.63–5.59 (m, 1 H), 4.34 (q, 2 H, J ¼ 7:9 Hz), 3.03–2.82
(m, 1 H), 2.18–2.01 (m, 2 H), 1.83–1.79 (m, 2 H), 1.71–
1.52 (m, 2H), 1.36 (t, 3 H, J ¼ 7:0 Hz) 19F NMR
(254 MHz, CDCl3) d: ꢂ33.31 (dd, 1 F, J ¼ 253:4, 14.7),
ꢂ29.11 (dd, 1 F, J ¼ 253:4, 14.7) MS (m/z) 204 (Mþ), 131.
HRMS m/z calced for C10H14F2O2: 204.0962. Found:
204.0960.
3.4.11. trans-Ethyl 5-t-butoxy-2,2-difluoro-3-butenoate
(6e)
1H NMR (270 MHz, CDCl3) d: 6.99 (dt, 1 H, J ¼ 12:4,
2.7 Hz), 5.13 (dd, 1 H, J ¼ 12:4, 11.9 Hz), 4.31 (q, 2 H,
J ¼ 7:0 Hz), 1.34 (t, 3 H, J ¼ 7:3 Hz), 1.31 (s, 9 H) 19F
NMR (254 MHz, CDCl3) d: ꢂ22.84 (d, 2 F, J ¼ 14:7 Hz)
MS (m/z) 222 (Mþ), 149. HRMS m/z calced for C10H16F2O2:
222.1068. Found: 222.1081.
Acknowledgements
3.4.12. cis-Ethyl 5-t-butoxy-2,2-difluoro-3-butenoate (6e)
1H NMR (270 MHz, CDCl3) d: 6.51 (d, 1 H, J ¼ 6:8 Hz),
4.79 (dt, 1 H, J ¼ 6:8, 9.5 Hz), 4.31 (q, 2 H, J ¼ 7:3 Hz),
We are grateful to Morita Chemical Co. Ltd. for generous
gifts of Et3Nꢁ3HF and Et3Nꢁ5HF.