D. Chevrie et al. / Tetrahedron 58 32002) 4759±4767
4765
3
&100), 43 &83); HRMS &EI) m/z calcd for C12H21FO2
216.1525, found 216.1565.
1.31 &s, 6H, CH3), 1.96 &d, JHH8.4 Hz, 1H, CH), 2.21
3
&dd, JHH8.4, 10.4 Hz, 1H, CH cyclopropyl), 3.68 &s, 3H,
3
CO2Me), 3.81&s, 3H, CO Me), 6.61&dd, JHH10.4 Hz,
2
5.3.2. Methyl-/Z),/E)-2-¯uoro-3-ethoxycarbonylprop-2-
enoate /3e). Colourless oil, 156 mg, yield 58%, selectivity
3JHF32.4 Hz, 1H, CHvCF); 19F NMR &CDCl3) d
2132.7 &d, JHF32.4 Hz, 1F, &Z) CFvCH), 13C NMR
3
1
3
3
Z/E: 87/13. H NMR &CDCl3) d 1.31 &t, JHH7.0 Hz, 3H,
Me E), 1.32 &t, 3JHH7.2 Hz, 3H, Me Z), 3.89 &s, 3H, OMe
E), 3.90 &s, 3H, OMe Z), 4.26 &q, 3JHH7.0 Hz, CH2 E), 4.26
&CDCl3) d 14.8 &Me), 27.9 &d, JCF4.9 Hz, CH), 28.3
&Me), 28.4 &CIV), 32.8 &CH), 51.5 &OMe), 52.2 &OMe),
2
1
116.4 &d, JCF7.2 Hz, CH), 149.0 &d, JCF253.9 Hz,
3
3
2
&q, JHH7.2 Hz, CH2 Z), 6.09 &d, JHF16.0 Hz, CHvCF
CF), 160.7 &d, JCF35.6 Hz, CvO), 170.7 &CvO);
E), 6.35 &d, JHF29.0 Hz, CHvCF Z); 19F NMR &CDCl3)
MS m/z &relative intensity) 230 &13), 200 &6), 199 &4),
3
3
d2111.6 &d, JHF16.5 Hz, 1F, CFvCH E), 2107.5 &d,
172 &12), 59 &54), 40 &100); IR &NaCl) 1732 cm21
;
HRMS &EI) m/z calcd for C11H15O4F 230.0954, found
230.0972.
3JHF28.2 Hz, 1F, CFvCH Z); 13C NMR &CDCl3) d 13.8
&Me E), 13.9 &Me Z), 52.9 &OCH3 E), 53.2 &OCH3 Z), 61.2
&CH2 Z), 61.6 &CH2 E), 108.0 &d, 2JCF3.1Hz, CH Z), 108.9
&d, 2JCF21.4 Hz, CH E), 153.7 &d, 1JCF288.3 Hz, CH Z),
5.3.5. Methyl-3-ethoxycarbonyl-3-chloro-3-¯uoro-pro-
2
2
1
3
162.2 &d, JCF34.8 Hz, CvO Z), 162.9 &d, JCF2.8 Hz,
CvO Z); MS m/z &relative intensity) 176 &5), 161 &1.82),
131 &31), 59 &40), 53 &21), 45 &100), 43 &72); IR &NaCl)
1732 cm21 &CvO). HRMS &EI) m/z calcd for C7H9FO4
176.0484, found 176.0475.
panoate /6). H NMR &CDCl3) d 1.24 &q, JHH7.2 Hz,
3
3H, Me 6a), 1.27 &q, JHH7.2 Hz, 3H, Me 6b), 3.75 &d,
5JHF0.9 Hz, 3H, OMe 6b), 3.79 &d, JHF1.0 Hz, 3H,
5
OMe 6a), 4.16±4.30 &m, 4H, OCH2 6a and b), 4.60 &d br,
3JHF30.9 Hz, 1H, CHCl 6a), 4.63 &dd, JHF23.9 Hz,
3
3JHH2.0 Hz, 1H, CHCl 6b), 5.19 &d, JHF47.3 Hz, 1H,
2
2
5.3.3. Methyl-2-¯uoro-4,5-O,O-cyclohexylidendioxy-pent-
2-enoate /3f). Colourless oil, 149 mg, yield 40%, selectivity
Z/E: 43/57) 1H NMR &CDCl3) d 1.40±1.42 &m, 10H, cyclo-
hexyl Z), 1.59±1.67 &m, 10H, cyclohexyl E), 3.66 &dd,
CHF 6a), 5.20 &d, JHF47.3 Hz, 1H, CHF 6b); 19F NMR
2
3
&CDCl3) d 2202.6 &dd, JHF47.3 Hz, JHF23.9 Hz, 1F,
2
3
CHF 6b), 2207.5 &dd, JHF47.3 Hz, JHF30.9 Hz, 1F,
CHF 6a); 13C NMR &CDCl3) d 13.8 &Me 6b), 13.9 &Me
6a), 52.5 &OMe 6b), 52.7 &OMe 6a), 62.7 &OCH2 6b),
3
3JHH6.4, 8.3 Hz, 1H, CH E), 3.69 &dd, JHH6.8, 8.4 Hz,
2
1H, CH Z), 3.84 &s, 3H, CO2Me Z), 3.85 &s, 3H, CO2Me E),
62.8 &OCH2 6a), 71.1 &d, JCF20.86 Hz, CHCl 6a), 71.3
3
4.20 &dd, JHH6.3, 8.3 Hz, 1H, CH Z), 4.28 &ddd,
&d, 2JCF21.8 Hz, CHCl 6b), 88.8 &d, 1JCF192.7 Hz, CHF
5
1
3JHH6.8, 7.9 Hz, JHF0.4 Hz, 1H, CH E), 5.02 &dddd,
6a), 89.7 &d, JCF193.5 Hz, CHF 6b), 166.7 &d,
3JHH8.0, 6.5, 6.5 Hz, JHF1.5 Hz, 1H, CH Z), 5.39
2JCF23.7 Hz, CvO 6b), 166.9 &d, JCF24.7 Hz, CvO
4
2
3
3
&ddd, JHH7.5, 6.2, 6.2 Hz, 1H, CH E), 6.03 &dd,
6a), 169.5 &d, JCF8.6 Hz, CvO 6b), 169.9 &d,
3
3JHH6.0, 19.2 Hz, CH E), 6.19 &dd, JHH6.1, 33.0 Hz,
3JCF2.9 Hz, CvO 6a).
4
CH Z); 19F NMR &CDCl3) d 2126.4 &dd, JHF2.3 Hz,
3
3JHF32.9 Hz, CF Z), 2121.0 &d, JHF21.1 Hz, CF E);
5.3.6. Methyl-2-/4-tert-butyl-1-hydroxy-cyclohexyl)-2-
terbutylsulfanyl-2-¯uoroacetate /7). To a solution of
anhydrous THF cooled at 2788C was added diisopropyl-
amine &1.2 equiv., 3.34 mmol, 0.467 mL). After 20 min,
1.2 M BuLi/hexane solution &1.1 equiv., 3.06 mmol,
2.54 mL) was slowly added and the solution warmed up at
2208C for 15 min. The mixture was cooled at 2788C and
the ¯uorosul®de 1 &500 mg, 2.78 mmol) added to the LDA
solution. After 30 min, 4-tert-butylcyclohexanone &1equiv.,
2.78 mmol, 428 mg) was introduced into the solution main-
tained at 2788C. The reaction mixture was stirred for 2 h
and diluted at 2788C with an aqueous solution of ammo-
nium chloride. The solution was extracted with dichloro-
methane, washed with saturated NaCl solution, dried over
MgSO4 and concentrated under vacuum. The a-¯uoro b-hy-
droxy tert-butylsulfanyl ester &7) obtained as an oil
&690 mg) was directly introduced in the next step without
13C NMR &CDCl3) d 23.8, 23.9 &CH2 cyclohexyl E), 25.0
&CH2 cyclohexyl Z), 25.2 &CH2 cyclohexyl E), 27.0 &CH2
cyclohexyl Z), 34.9 &CH2 cyclohexyl E), 35.1, 36.2 &CH2
cyclohexyl Z), 36.3 &CH2 cyclohexyl E), 37.3 &CH2 cyclo-
4
hexyl Z), 52.5 &OMe), 52.7 &OMe), 68.4 &d, JCF2.8 Hz,
4
CH2 Z), 68.9 &d, 3JCF3.5 Hz, CH Z), 69.1&d, JCF3.6 Hz,
CH2 E), 70.4 &d, 3JCF7.8 Hz, CH E), 110.6 &CIV E), 110.7
2
&CIV Z), 118.9 &d, JCF8.4 Hz, CH Z), 123.5 &d,
1
2JCF18.2 Hz, CH E), 147.3 &d, JCF261.6 Hz, CF E),
1
CF Z isomer not observable, 160.8 &d, JCF34.7 Hz,
CvO E), CvO Z isomer not observable; MS m/z &relative
intensity) 244 &32), 215 &27), 201 &100), 55 &79); IR &NaCl)
1740 &CvO E), 1672 cm21 &CvO Z); HRMS &EI) m/z calcd
for C12H17FO4 244.1110, found 244.1123.
5.3.4. /Z),/E)-cis-Methyl-2,2-dimethyl-3-/2-¯uoro-2-meth-
oxycarbonyl)ethylidene)cyclopropanecarboxylate /3g).
Colourless oil, 266 mg, yield 76%, selectivity Z/E: 77/23.
1
puri®cation. H NMR &CDCl3) d 0.71&s, 9H, tBu), 0.79±
1.68 &m, 6H, cyclohexyl), 1.24 &s, 9H, tBu), 1.90±1.99 &m,
2H, CH2), 2.19±2.23 &m, 1H, CH), 2.59 &s, 1H, OH), 3.71 &s,
3H, CO2Me); 19F NMR &CDCl3) d 2146.1 &s, 1F, CF); 13
1
[113894-36-3]: E isomer H NMR &CDCl3) d 1.27 &s, 6H,
3
2CH3 cyclopropyl), 1.91 &dd, JHH8.5, 10.3 Hz, 1H, CH
C
3
3
cyclopropyl), 2.84 &t, JHH8.5 Hz, 1H, CH cyclopropyl),
NMR &CDCl3) d 21.7 &d, JCF11.7 Hz, CH2), 27.1&CH ),
3
3.66 &s, 3H, CO2Me), 3.84 &s, 3H, CO2Me), 6.44 &dd,
27.2 &CH2), 31.3 &CH2), 31.4 &CH3 tBu), 31.9 &CH2), 32.2
3
4
3JHH10.3 Hz, JHF20.8 Hz, 1H, CHvCF); 19F NMR
&d, JCF1.7 Hz, CH2), 40.8 &tBu), 46.28 &tBu), 46.9
4
3
2
&CDCl3) d 2121.3 &dd, JHF1.0 Hz, JHF20.8 Hz, 1F,
&CH cyclohexyl), 52.4 &OMe), 75.9 &d, JCF20.9 Hz,
&E) CFvCH); 13C NMR &CDCl3) d 14.7 &Me), 28.4 &Me),
COH), 106.7 &d, JCF238.4 Hz, CF), 169.8 &d,
1
3
28.4 &CIV), 28.8 &d, JCF7.4 Hz, CH), 32.4 &CH), 51.4
2JCF33.0 Hz, CvO); MS m/z &relative intensity) 334 &7),
180 &64), 155 &48), 137 &20), 124 &96), 98 &12) 81 &16), 57
&100); HRMS &EI) m/z calcd for C17H31FO3S 334.1978,
found &M)1 334.1940.
2
&OMe), 52.0 &OMe), 120.0 &d, JCF24.6 Hz, CH), 147.8
1
2
&d, JCF252.1 Hz, CF), 161.6 &d, JCF34.5 Hz, CvO),
1
170.9 &CvO); Z isomer H NMR &CDCl3) d 1.27 and