A new α-seleno- or nonselenoperfluoroacyl olefination of aldehydes and ketones using β-ethoxy-β-perfluoroalkyl vinylic selenides

Full text of DOI:10.1021/jo0003246

4456
J . Org. Chem. 2000, 65, 4456-4459
by the elimination of the phenylselenenyl group using
methanesulfonyl chloride (Scheme 2).9 We first examined
the deprotonation of the vinylic selenides by a few amide
bases (method A).10 LTMP was found to be effective in
their deprotonation of 2 and the reaction with benzalde-
hyde afforded the (E)-2-(phenylseleno)allylic alcohol 6a
in 72% yield. The isomerization of 6a by p-toluenesulfonic
acid (1.1 equiv) gave (Z)-1,1,1-trifluoro-4-phenyl-3-(phe-
nylseleno)but-3-en-2-one (14a ) in 53% yield. Spectro-
scopic data, by showing the carbonyl absorption at ν 1710
cm-1 in the IR spectrum, exhibiting the olefinic proton
at δ 8.14 ppm in the 1H NMR spectrum, and also showing
the trifluoromethyl carbon at δ 116.3 (J C-F ) 293 Hz) and
the 2-C at δ 180.1 (J C-F ) 26 Hz) in the 13C NMR
spectrum, indicated that the product was R,â-unsatur-
ated trifluoromethyl ketone. We also examined the R-se-
leno trifluoroacetyl olefination of the other aldehydes and
the results are shown in Table 1. (E)-Cinnamaldehyde
and phenylpropargyl aldehyde gave the trifluoromethyl
ketones 14b,c (Entries 2 and 3); however, the reaction
of 2 with ketones such as cyclopentanone did not afford
the allylic alcohols.
Next, we performed the lithiation of 2 by transmeta-
lation (method B) and examined the reaction with mesityl
aldehyde. The allylic alcohol 7a was obtained in moderate
yield, accompanied by n-butyl phenyl selenide. The
isomerization of 7a under the same condition afforded
the R,â-unsaturated trifluoromethyl ketone 15a (entry
4). The trifluoroacetyl olefinations of the ketones, such
as acetophenone and cyclododecanone, proceeded in good
yields (entries 5 and 7). Furthermore, we performed the
R-seleno olefination using â-pentafluoroethyl vinylic se-
lenide 3 with aldehydes to afford the corresponding
pentafluoroethyl ketones 17a ,b (entries 8 and 9). Non-
selenium-type olefinations of the aldehyde and ketone
exclusively gave the ketones 18a ,b (entries 10 and 11).
The R-thio perfluoroacyl olefinations, which have previ-
ously been reported, are quite limited for the pentafluo-
ropropionyl olefinations because the â-pentafluoroethyl
vinylic sulfide could be obtained only in low yields.4 This
perfluoroacyl olefinations reported here are versatile and
suitable for the preparations of the R,â-unsaturated
perfluoroalkyl ketones bearing the long perfluoroalkyl
groups. The heptafluoropropionyl or the nonafluorov-
aleryl olefinations using the vinylic selenide 4,5 gave the
R,â-unsaturated ketones 19-22 (entries 12-15).
A New r-Selen o- or Non selen op er flu or oa cyl
Olefin a tion of Ald eh yd es a n d Keton es
Usin g â-Eth oxy-â-p er flu or oa lk yl Vin ylic
Selen id es
Yoshiaki Matsubara and Mitsuhiro Yoshimatsu*
Department of Chemistry, Faculty of Education,
Gifu University, Yanagido, Gifu 501-11, J apan
Received March 7, 2000
â-Alkoxy vinylic chalcogenides can be easily lithiated
by treatment with strong base, and subsequent reactions
with aldehydes and ketones afford the 2-chalcogeno
allylic alcohols, which are potentially versatile precursors
for the 2-chalcogene-substituted allylic cations1 or their
hydrolysis allows the R-chalcogeno formyl olefination of
aldehydes and ketones.2,3
To explore the R-chalcogene-substituted olefination, we
planned to investigate the perfluoroacyl olefination of the
aldehydes and ketones using the R-lithio-â-perfluoroalkyl
vinylic chalcogenides. R-(Methylthio)- or R-(phenylthio)-
perfluoroacyl olefinations of the nonenolizable aldehydes
have already reported to afford R-(thio)-R,â-unsaturated
ketones in high yields;4 however, the R-seleno perfluo-
roacyl olefination could not be examined because â-alkoxy-
â-perfluoroalkyl vinylic selenides were difficult to prepare
by the same method as the sulfur analogues. It is a more
efficient route than that of the R-thio-substituted olefi-
nation because a new perfluoroalkyl vinylic selenide could
provide two kinds of vinyllithiums by deprotonation or
transmetalation (Scheme 1).5 The reactions of each
vinyllithium with aldehydes and ketones and the follow-
ing process would accomplish the R-seleno or nonseleno
perfluoroacyl olefination,6-8 respectively. Here we report
a novel R-seleno- or nonseleno perfluoroacyl olefination
of the aldehydes and ketones using â-ethoxy-â-perfluo-
roalkyl vinylic selenides.
Preparations of the â-ethoxy-â-perfluoroalkyl vinylic
selenides 2-5 were performed by our original method.
The vinylic selenides were obtained from the reactions
between the lithiated5 bis(phenylseleno)methane (1)
generated by the treatment with lithium 2,2,6,6-tetram-
ethylpiperidide (LTMP) and RfCO2Et at -50 °C followed
(1) Yoshimatsu, M.; Gotoh, S.; Ikeda, K.; Komori, M. J . Org. Chem.
1998, 63, 6619-6624.
We also examined the tandem olefination of the R,â-
unsaturated perfluoroalkyl ketones as shown in Scheme
3. It is noteworthy that the treatment of the dienyl
alcohols 23 and 24 with acid afforded the 4,6-bis-
(perfluoroalkyl)-2H-pyrans 25 and 26, accompanied by
the 1,3-butadienyl perfluoroalkyl ketone acetals 27
and 28, not the dienyl ketone 29. Much attention has
been paid to the fluorinated heterocycles;11 so that, they
(2) Yoshimatsu, M.; Oguri, K.; Ikeda, K.; Gotoh, S. J . Org. Chem.
1998, 63, 4475-4480.
(3) Yoshimatsu, M.; Gotoh, S.; Tanabe, G.; Muraoka, O. Chem.
Commun. 1999, 909-910.
(4) For general experimental procedures, see: Yoshimatsu, M.;
Sugimoto, T.; Okada, N.; Kinoshita, S. J . Org. Chem. 1999, 64, 5162-
5165.
(5) Groebel, T.-G.; Seebach, D. Chem. Ber. 1977, 110, 867-877.
Other bases were found less effective in the generation of the
vinyllithium: Yoshimatsu, M.; Kinoshita, S. Chem. Pharm. Bull. 2000,
48, 415-417.
(6) Aldol condensation: Vlattas, I.; Vecchia, L. D.; Lee, A. O. J . Am.
Chem. Soc. 1976, 98, 2008-2010. Mead, D.; Loh, R.; Asato, A. E.; Lin,
R. S. H. Tetrahedron Lett. 1985, 26, 2873-2876. Katsuyama, I.;
Funabiki, K.; Matsui, M.; Muramatsu, H.; Shibata, K. Chem. Lett.
1996, 179-180.
(7) Iminophosphonate route: Huang, W. S.; Yuan, C. Y. J . Chem.
Soc., Perkin Trans. 1 1995, 741-742.
(8) Conjugate addition of the high order cyano cuprate to acetylenic
trifluoromethyl ketone: Linderman, R. J .; Lonikar, M. S. J . Org. Chem.
1988, 53, 6013-6022.
(9) Denis, J . M.; Desauvage, S.; Hevesi, L.; Krief, A. Tetrahedron
Lett. 1981, 22, 4009-4012.
(10) Seebach, D.; Peleties, N. Chem. Ber. 1972, 105, 511-520.
Burton, A.; Hevesi, L.; Dumont, W.; Cravador, A.; Krief, A. Synthesis
1979, 877-880. Raucher, S.; Koolpe, G. A. J . Org. Chem. 1978, 43,
3794-3796.
(11) Filler, R. In Organofluorine Chemicals and Their Industrial
Applications; Banks, R. E., Ed.; Ellis Horwood: London, 1979; p 123.
Biomedicinal Aspect of Fluorine Chemistry; Filler, R., Kobayashi, Y.,
Eds.; Kodansha & Elsevier Biomedical: Tokyo, 1982; p 1.
10.1021/jo0003246 CCC: $19.00 © 2000 American Chemical Society
Published on Web 06/09/2000

Notes
J . Org. Chem., Vol. 65, No. 14, 2000 4457
Sch em e 1
Sch em e 2a
t, J ) 7 Hz), 2.83 (1H, s), 3.82-3.98 (2H, m), 5.97 (1H, d, J ) 7
Hz), 7.13-7.20 (3H, m), 7.21-7.35 (7H, m); 13C NMR δ 15.2 (q),
69.3 (t), 70.1 (d, q, J ) 3 Hz), 121.0 (s, q, J ) 280 Hz), 125.8 (d
× 2), 127.6 (d), 128.4 (d × 2), 129.1 (d × 2), 129.4 (s), 132.7 (d ×
2), 134.2 (s), 140.7 (s), 145.0 (s, q, J ) 33 Hz); 19F NMR δ -18.13
(3F, s); MS m/z 402 (M+). Anal. Calcd for C18H17F3O2Se: C, 53.88;
H, 4.27. Found: C, 53.84; H, 4.32.
a
Reagent: (i) lithium 2,2,6,6-tetramethylpiperidide (LTMP)/
(Z)-2-Eth oxy-1,1,1-tr iflu or o-4-m esitylbu t-2-en -4-ol (7a ):
1H NMR δ 1.32 (3H, t, J ) 7 Hz), 2.24 (3H, s), 2.40 (6H, s), 3.68-
3.83 (2H, m), 5.37 (1H, d, J ) 9 Hz), 6.03 (1H, dd, J ) 9, 1 Hz),
6.82 (2H, s); 13C NMR δ 14.2 (q), 20.7 (q × 2), 20.9 (q), 64.6 (t),
65.0 (d, q, J ) 2 Hz), 108.0 (d), 120.8 (s, q, J ) 276 Hz), 130.5 (d
× 2), 135.8 (s), 136.3 (s × 2), 137.4 (s), 145.9 (s, q, J ) 34 Hz);
19F NMR δ -12.23 (3F, s); MS m/z 273 (M+ - Me). Anal. Calcd
for C15H19F3O2: C, 62.49; H, 6.64. Found: C, 62.69; H, 6.72.
(E)-3-Eth oxy-1,1,1,2,2-p en ta flu or o-6,6-d im eth yl-4-(p h e-
n ylselen o)h ep t-3-en -5-ol (8a ): 1H NMR δ 0.97 (9H, s), 1.13
(3H, t, J ) 7 Hz), 2.84 (1H, dd, J ) 10, 1 Hz), 3.82-3.90 (1H,
m), 4.19-4.26 (1H, m), 4.56 (1H, d, J ) 10 Hz), 7.19-7.23 (3H,
m), 7.41-7.43 (2H, m); 13C NMR δ 15.3 (q), 26.9 (q × 3), 36.6
(s), 70.2 (t), 74.3 (d, t, J ) 13 Hz), 111.7 (s, qt, J ) 37, 259 Hz),
118.8 (s, qt, J ) 37, 288 Hz), 127.5 (d), 129.2 (d × 2), 131.1 (d ×
2), 131.4 (s), 138.1 (s), 144.7 (s, t, J ) 24 Hz); 19F NMR δ -33.25
(1F, d, J ) 273 Hz), -31.77 (1F, d, J ) 273 Hz), -5.62 (3F, t, J
) 2 Hz); MS m/z 432 (M+). Anal. Calcd for C17H21F5O2Se: C,
47.34; H, 4.91. Found: C, 47.40; H, 4.85.
RfCO2Et/MsCl/-50 °C.
would be expected to show the interesting biological
activities.12 Now we are examining the further investiga-
tion of the uneque 4,6-bis(perfluoroalkyl)pyran forma-
tions. These results will be reported elsewhere.
Exp er im en ta l Section 4
P r ep a r a tion of (E)-2-Eth oxy-1,1,1-tr iflu or o-3-(p h en ylse-
len o)p r op -2-en e (2). Typ ica l P r oced u r e. A THF (8.00 mL)
solution of bis(phenylseleno)methane (1) (6.00 g, 18.4 mmol) was
added dropwise to a THF (30.0 mL) solution of lithium 2,2,6,6-
tetramethylpiperidide [prepared from 2,2,6,6-tetramethylpip-
eridine (3.90 g, 27.6 mmol) and n-BuLi (16.0 mL of 1.50 M
n-BuLi in n-hexane solution, 23.9 mmol)] under an Ar atmo-
sphere at -50 °C. The mixture was stirred for 10 min, ethyl
trifluoroacetate (6.60 mL, 55.2 mmol) and then methanesulfonyl
chloride (3.16 g, 27.6 mmol) was added dropwise to it. The whole
was stirred for 10 min and poured into water (150 mL). The
organic layer was separated and the aqueous layer was extracted
with ether. The combined organic layer was dried over MgSO4.
The solvent was removed under reduced pressure. The residue
was purified by column chromatography on silica gel eluting with
hexane to give the title compound 2 (2.31 g, 43%) as a pale yellow
oil.
(Z)-3-Eth oxy-1,1,1,2,2-p en ta flu or o-5-m esitylp en t-3-en -5-
1
ol (9a ): H NMR δ 1.31 (3H, t, J ) 7 Hz), 1.95 (1H, brs), 2.25
(3H, s), 2.41 (6H, s), 3.71-3.86 (2H, m), 5.55 (1H, d, J ) 9 Hz),
6.06 (1H, dt, J ) 9, 2 Hz), 6.83 (2H, s); 13C NMR δ 14.2 (q), 20.8
(q × 2), 20.9 (q), 64.7 (t), 64.8 (d, t, J ) 3 Hz), 111.1 (d), 111.3 (s,
qt, J ) 37, 260 Hz), 118.9 (s, qt, J ) 37, 288 Hz), 130.5 (d × 2),
136.0 (s), 136.3 (s × 2), 137.5 (s), 145.2 (s, J ) 27 Hz); 19F NMR
δ -37.68 (1F, d, J ) 282 Hz), -36.46 (1F, d, J ) 282 Hz), -5.24
(3F, s); MS m/z 219 (M+ - mesityl). Anal. Calcd for C16H19F5O2:
C, 56.80; H, 5.66. Found: C, 57.21; H, 5.68.
(E )-2-E t h oxy-1,1,1-t r iflu or o-3-(p h e n ylse le n o)p r op -2-
en e (2): 1H NMR (400 MHz, CDCl3) δ 1.34 (3H, t, J ) 7 Hz),
3.82 (2H, q, J ) 7 Hz), 5.80 (1H, s), 7.30-7.31 (3H, m), 7.52-
7.54 (2H, m); 13C NMR (100 MHz, CDCl3) δ 14.4 (q), 65.3 (t),
97.7 (d), 120.9 (s, q, J ) 275 Hz), 128.1 (d), 129.7 (d × 2), 131.0
(s), 132.7 (d × 2), 143.5 (s, q, J ) 34 Hz); 19F NMR (376.4 MHz,
CDCl3) δ -10.98 (3F, s); MS m/z 139 (M+ - PhSe). Anal. Calcd
for C11H11F3OSe: C, 44.76; H, 3.76. Found: C, 44.81; H, 3.74.
(E)-3-Eth oxy-1,1,1,2,2-p en ta flu or o-4-(p h en ylselen o)bu t-
(E)-4-Eth oxy-1,1,1,2,2,3,3-h eptaflu or o-7,7-dim eth yl-5-(ph e-
n ylselen o)oct-4-en -6-ol (E)-(10): 1H NMR δ 0.96 (9H, s), 1.36
(3H, t, J ) 7 Hz), 2.87 (1H, d, J ) 12 Hz), 3.89-3.93 (1H, m),
4.05-4.08 (1H, m), 4.53 (1H, d, J ) 12 Hz), 7.21-7.27 (3H, m),
7.44-7.46 (2H, m); 19F NMR δ -47.11 (2F, s), -33.98 (1F, dq, J
) 278, 9 Hz), -27.98 (1F, dq, J ) 278, 9 Hz), -2.56 (3F, t, J )
10 Hz); MS m/z 482 (M+). Anal. Calcd for C18H21F7O2Se: C,
44.92; H, 4.40. Found: C, 45.43; H, 4.47.
(Z)-4-Eth oxy-1,1,1,2,2,3,3-h ep ta flu or o-6-p h en ylh ex-4-en -
6-ol (11): 1H NMR δ 1.30 (3H, t, J ) 7 Hz), 2.20 (1H, brs), 3.69-
3.81 (2H, m), 5.23 (1H, d, J ) 10 Hz), 5.65 (1H, d, J ) 10 Hz),
7.23-7.39 (5H, m); 19F NMR δ -49.77 (2F, s), -35.74 (1F, dq, J
) 284, 9 Hz), -33.90 (1F, dq, J ) 284, 9 Hz), -2.87 (3F, t, J )
9 Hz); MS m/z 346 (M+). Anal. Calcd for C14H13F7O2: C, 48.56;
H, 3.78. Found: C, 50.98; H, 4.13.
(E)-5-Eth oxy-1,1,1,2,2,3,3,4,4-n on a flu or o-8,8-d im eth yl-6-
(p h en ylselen o)n on -5-en -7-ol (E)-(12): 1H NMR δ 0.96 (9H, s),
1.36 (3H, t, J ) 7 Hz), 2.86 (1H, d, J ) 12 Hz), 3.88-3.94 (1H,
m), 4.04-4.10 (1H, m), 4.52 (1H, d, J ) 12 Hz), 7.20-7.30 (3H,
m), 7.43-7.46 (2H, m); 19F NMR δ -49.17 to -48.29 (1F, m),
-47.77 to -46.91 (1F, m), -44.47 to -43.67 (1F, m), -43.37 to
-42.57 (1F, m), -33.04 (1F, brd, J ) 280 Hz), -27.84 (1F, brd,
J ) 280 Hz), -3.16 (3F, t, J ) 10 Hz); high-resolution mass calcd
for C19H21F9O2Se: 532.0562, found m/z 532.0554.
(Z)-5-Eth oxy-1,1,1,2,2,3,3,4,4-n on a flu or o-7-p h en ylh ep t-5-
en -7-ol (Z)-(13): 1H NMR δ 1.32 (3H, t, J ) 7 Hz), 1.57 (1H,
brs), 3.75-3.83 (2H, m), 5.26 (1H, d, J ) 10 Hz), 5.68 (1H, brd,
J ) 10 Hz), 7.28-7.44 (5H, m); 19F NMR δ -48.42 to -48.35
(2F, m), -46.03 to -45.95 (2F, m), -34.75 (1F, dt, J ) 282, 13
1
3-en e (3): H NMR δ 1.32 (3H, t, J ) 7 Hz), 3.83 (2H, q, J ) 7
Hz), 5.94 (1H, s), 7.30-7.33 (3H, m), 7.53-7.55 (2H, m); 13C
NMR δ 14.3 (q), 65.5 (t), 100.9 (d), 111.3 (s, tq, J ) 257, 39 Hz),
119.0 (s, qt, J ) 288, 39 Hz), 128.2 (d), 129.7 (d × 2), 131.7 (s),
132.9 (d × 2), 142.1 (s, t, J ) 26 Hz); 19F NMR δ -37.83 (2F, q,
J ) 1 Hz), -5.39 (3F, t, J ) 3 Hz); MS m/z 189 (M+ - PhSe).
Anal. Calcd for C12H11F5OSe: C, 41.76; H, 3.21. Found: C, 41.72;
H, 3.20.
P r ep a r a tion of (E)-2-Eth oxy-1,1,1-tr iflu or o-4-p h en yl-3-
(p h en ylselen o)bu t-2-en -4-ol (6a ). Typ ica l P r oced u r e. A
THF (1.00 mL) solution of (E)-2-ethoxy-1,1,1-trifluoro-3-(phe-
nylseleno)prop-2-ene (2) (0.30 g, 1.00 mmol) was added dropwise
to a THF (3.0 mL) solution of lithium 2,2,6,6-tetramethylpip-
eridide (prepared from 2,2,6,6-tetramethylpiperidine (0.28 g, 2.00
mmol) and n-BuLi (1.00 mL, 1.50 mmol)) under an Ar atmo-
sphere at -78 °C. The reaction mixture was stirred for 10 min.
A THF (1.00 mL) solution of benzaldehyde (0.16 g, 1.50 mmol)
was added to the mixture. The workup procedure gave the title
compound 6a (0.29 g, 72%) as a yellow oil: 1H NMR δ 1.17 (3H,
(12) Hojo, M.; Masuda, R.; Okada, E. Synthesis 1989, 215-217.

4458 J . Org. Chem., Vol. 65, No. 14, 2000
Ta ble 1. r-Selen o or Non selen op er flu or oa cyl Olefin a tion s of Ald eh yd es a n d Keton es
Notes
enol ether
(Rf)
carbonyl compound
entry
R1
R2
conditions
Y
alcohol (% yield)
products (% yields)
1
2
3
4
5
2 (CF3)
Ph
(E)-PhCHdCH
phenylethynyl
Mesityl
H
H
H
H
Me
H
Aa
A
A
Bc
B
PhSe
PhSe
PhSe
H
H
H
(E)-6a (72)
(E)-6b (74)
(E)-6c (48)
(Z)-7a (51)
(Z)-7b (48)
(Z)-14a (53)
(Z)-14b (70)
2
2
2
2
2
2
(E)- and (Z)-14c (72)b
(E)-15a (95)
Ph
(E)-15b (62)
6
7
phenylethynyl
(CH2)11
B
B
(Z)-7c (57)
7d (55)
(E)-15c (71) (E)-16c (10)d
15d (68)
H
8
9
3 (CF2CF3)
t-Bu
(E)-PhCHdCH
Mesityl
(E)-PhCHdCH
t-Bu
H
H
H
Me
H
H
A
A
B
B
A
B
PhSe
PhSe
H
H
PhSe
H
(E)-8a (64)
(E)-8b (65)
(Z)-9a (68)
(Z)-17a (94)
(Z)-17b (79)
3
3
3
10
11
12
13
14
15
(E)-18a (96)
(Z)-9b (47)
(E)- and (Z)-18b (91)e
(Z)-19 (90)
4 (CF2CF2CF3)
(E)- and (Z)-10 (43)f
(Z)-11 (61)
4
Ph
t-Bu
Ph
(E)-20 (90)
(Z)-21 (58)
(E)-22 (78)
5 (CF2CF2CF2CF3)
H
H
A
B
PhSe
H
(E)- and (Z)-12 (62)g
(Z)-13 (73)
5
a
b
Condition A: lithium 2,2,6,6-tetramethylpiperidide/THF/-78 °C/aldehydes. E/Z ) 31:69. c Condition B: BuLi/THF/-78 °C/aldehydes
or ketones. 16c: (E)-2,2-diethoxy-1,1,1-trifluoro-6-phenylhex-3-en-5-yne. e E/Z ) 65:35. f E:Z ) 98:2. E/Z ) 37:63.
d
g
Sch em e 3a
a
Reagents: (i) BuLi/Rf(EtO)CdCHSePh/-78 °C; (ii) TsOH/83 °C.
Hz), -32.87 (1F, dt, J ) 282, 13 Hz), -3.11 (3F, t, J ) 10 Hz);
high-resolution mass calcd for C15H13F9O2 396.0771, found m/z
396.0758.
m), 7.28 (1H, brs), 7.38-7.40 (2H, m); 13C NMR δ 30.0 (Me ×
3), 36.0 (s), 107.6 (s, qt, J ) 271, 37 Hz), 118.0 (s, qt, J ) 288,
37 Hz), 127.5 (s), 127.9 (d), 129.2 (s), 129.6 (d × 2), 132.6 (d ×
2), 163.2 (d), 182.7 (s, t, J ) 26 Hz); 19F NMR δ -36.32 (2F, d,
J ) 1 Hz), -3.81 (3F, s); MS m/z 386 (M+). Anal. Calcd for
C15H15F5OSe: C, 46.69; H, 3.94. Found: C, 46.77; H, 3.92.
(E)-1,1,1,2,2-P en ta flu or o-5-m esitylp en t-4-en -3-on e (18a ):
yellow needles; mp 44-47 °C; 1H NMR δ 2.30 (3H, s), 2.39 (6H,
s), 6.81 (1H, d, J ) 16 Hz), 6.93 (2H, s), 8.24 (1H, d, J ) 16 Hz);
13C NMR δ 21.3 (q), 21.5 (q × 2), 108.1 (s, qt, J ) 38, 266 Hz),
118.4 (s, qt, J ) 35, 287 Hz), 121.4 (d), 129.8 (s), 130.2 (d × 2),
138.9 (s × 2), 141.1 (s), 148.5 (d), 182.5 (s, qt, J ) 26 Hz); 19F
NMR δ -46.29 (2F, s), -4.32 (3F, s); MS m/z 173 (M+ - CF2-
CF3). Anal. Calcd for C14H13F5O: C, 57.54; H, 4.48. Found: C,
57.44; H, 4.47.
(2Z,5E)-2-E t h oxy-1,1,1-t r iflu or o-6-m esit yl-4-(t r iflu or o-
m eth yl)h ex-2,5-d ien -4-ol (23): 1H NMR δ 1.40 (3H, t, J ) 7
Hz), 2.21 (6H, s), 2.25 (3H, s), 2.71 (1H, s), 3.17 (2H, q, J ) 7
Hz), 5.25 (1H, s), 5.75 (1H, d, J ) 16 Hz), 6.78 (1H, d, J ) 16
Hz), 6.85 (2H, s); 13C NMR δ 14.1 (q), 20.6 (q × 2), 21.2 (q), 65.2
(t), 75.4 (s, q, J ) 28 Hz), 102.9 (d), 119.8 (s, q, J ) 276 Hz),
125.2 (s, J ) 286 Hz), 128.9 (d × 2), 129.7 (d), 132.6 (s), 133.1
(d), 136.2 (s × 2), 137.2 (s), 149.4 (s, q, J ) 37 Hz); 19F NMR δ
-16.06 (3F, s), 1.45 (3F, s); MS m/z 382 (M+). Anal. Calcd for
C18H20F6O2: C, 56.55; H, 5.27. Found: C, 56.54; H, 5.34.
P r ep a r a tion of (Z)-1,1,1-Tr iflu or o-4-p h en yl-3-(p h en ylse-
len o)bu t-3-en -2-on e (14a ). Typ ica l P r oced u r e. A ClCH2CH2-
Cl (3.00 mL) solution of 6a (0.26 g, 0.65 mmol) and p-toluene-
sulfonic acid (0.16 g, 0.84 mmol) was heated at 83 °C for 10 min.
The mixture was poured into a saturated NaHCO3 (50.0 mL).
The workup procedure afforded the title compound (0.12 g, 53%)
as a yellow oil: 1H NMR δ 7.19-7.23 (3H, m), 7.35-7.45 (5H,
m), 7.76-7.78 (2H, m), 8.14 (1H, s); 13C NMR δ 116.3 (s, q, J )
293 Hz), 127.3 (s), 127.9 (d), 128.7 (d × 2), 129.4 (s), 129.6 (d ×
2), 131.3 (d × 2), 131.41 (d), 132.3 (d × 2), 134.4 (s), 150.4 (d, q,
J ) 3 Hz), 180.1 (s, q, J ) 26 Hz); 19F NMR δ -13.63 (3F, s);
MS m/z 356 (M+). Anal. Calcd for C16H11F3OSe: C, 54.10; H,
3.12. Found: C, 54.04; H, 3.22.
(Z)-1,1,1,2,2,3,3-Hep ta flu or o-7,7-d im eth yl-5-(p h en ylsele-
n o)oct-5-en -4-on e (19): 1H NMR δ 1.37 (9H, s), 7.21 (1H, s),
7.23-7.26 (3H, m), 7.39-7.42 (2H, m); 19F NMR δ -47.74 (2F,
t, J ) 7 Hz), -34.02 (2F, q, J ) 9 Hz), -4.08 (3F, s); MS m/z
436 (M+). Anal. Calcd for C16H15F7OSe: C, 44.15; H, 3.47.
Found: C, 44.24; H, 3.41.
(E)-1,1,1,2,2,3,3-Heptaflu or o-6-ph en ylh ex-5-en -4-on e (20):
1H NMR δ 7.18 (1H, d, J ) 16 Hz), 7.40-7.53 (3H, m), 7.64-
7.67 (2H, m), 7.98 (1H, d, J ) 16 Hz); 19F NMR δ -48.93 (2F, s),
-44.07 (2F, q, J ) 9 Hz), -2.80 (3F, t, J ) 9 Hz); high-resolution
mass calcd for C12H7F7O 300.0385, found m/z 300.0378.
(Z)-1,1,1,2,2,3,3,4,4-Non a flu or o-8,8-d im eth yl-6-(p h en ylse-
len o)n on -6-en -5-on e (21): 1H NMR δ 1.37 (9H, s), 7.20 (1H,
s), 7.24-7.27 (3H, m), 7.39-7.42 (2H, m); 19F NMR δ -47.53 to
-47.46 (2F, m), -43.95 to -43.88 (2F, m), -33.19 (2F, brt, J )
13 Hz), -3.24 (3F, tt, J ) 10, 3 Hz); MS m/z 486 (M+). Anal.
Calcd for C17H15F9OSe: C, 42.08; H, 3.12. Found: C, 42.28; H,
3.12.
(E)-1,1,1-Tr iflu or o-4-m esitylbu t-3-en -2-on e (15a ): mp 19-
20 °C; 1H NMR δ 2.13 (3H, s), 2.29 (6H, s), 6.68 (1H, dd, J ) 16,
1 Hz), 6.92 (2H, s), 8.20 (1H, d, J ) 16 Hz); 13C NMR δ 21.3 (q),
21.5 (q × 2), 116.7 (s, J ) 291 Hz), 121.3 (d), 129.9 (s), 130.1 (d
× 2), 138.6 (s × 2), 140.9 (s), 148.6 (d), 180.2 (s, q, J ) 35 Hz);
19F NMR δ -1.48 (3F, s); MS m/z 242 (M+). Anal. Calcd for
C
13H13F3O: C, 64.46; H, 5.41. Found: C, 64.33; H, 5.42.
(Z)-1,1,1,2,2-P en ta flu or o-6,6-d im eth yl-4-(p h en ylselen o)-
(E )-1,1,1,2,2,3,3,4,4-Non a flu or o-7-p h e n ylh e p t -6-e n -5-
h ep t-4-en -3-on e (17a ): 1H NMR δ 1.37 (9H, s), 7.22-7.25 (3H,
on e (22): 1H NMR δ 7.12 (1H, d, J ) 16 Hz), 7.42-7.53 (3H,

Notes
J . Org. Chem., Vol. 65, No. 14, 2000 4459
m), 7.65-7.68 (2H, m), 7.99 (1H, d, J ) 16 Hz); 19F NMR δ
-48.28 to -48.15 (2F, m), -45.76 to -45.62 (2F, m), -43.64 (2F,
t, J ) 12 Hz), -3.24 (3F, tt, J ) 9, 3 Hz); MS m/z 350 (M+).
Anal. Calcd for C13H7F9O: C, 44.59; H, 2.01. Found: C, 44.70;
H, 2.26.
s), 6.96 (1H, d, J ) 17 Hz), 7.02 (1H, d, J ) 17 Hz); 19F NMR δ
-4.14 (3F, s), 9.82 (3F, s); MS m/z 410 (M+). Anal. Calcd for
C
20H24F6O2: C, 58.53; H, 5.89. Found: C, 58.43; H, 5.73.
Ack n ow led gm en t. The support of a part of this
work by the Ministry of Education, Science and Culture,
J apan, is gratefully acknowledged.
2H-2-Mesityl-4,6-bis(tr iflu or om eth yl)p yr a n (25): 1H NMR
δ 2.28 (3H, s), 2.37 (6H, s), 5.92 (2H, brs), 6.51 (1H, brs), 6.90
(2H, s); 19F NMR δ -10.46 (3F, s), -6.62 (3F, s); MS m/z 335
(M+ - 1). Anal. Calcd for C16H14F6O: C, 57.15; H, 4.20. Found:
C, 57.09; H, 4.29. (3E,5E)-1,1,1-Trifluoro-6-mesityl-4-(trifluo-
Su p p or tin g In for m a tion Ava ila ble: Characterization
data for the products 4, 5, 6b,c, 7b-d , 8b, 9b, (Z)-12, 14b,c,
15b-d , 16c, 17b, and 18b and 1H and 19F NMR spectra,
complete with peak assignments of other products and full lists
of IR spectral data. This material is available free of charge
via the Internet at http://pubs.acs.org.
1
romethyl)hex-3,5-dien-2-one was observed by H NMR spectros-
copy at δ 6.74 (1H, brs), 6.92 (2H, s), 7.60 (1H, d, J ) 17 Hz),
7.75 (1H, d, J ) 17 Hz) and 19F NMR spectroscopy at δ -16.60
ppm.
(3E,5E)-2,2-Dieth oxy-1,1,1-tr iflu or o-6-m esityl-4-(tr iflu o-
r om eth yl)h ex-3,5-d ien e (27): 1H NMR (400 MHz, CDCl3) δ
1.22 (6H, t, J ) 7 Hz), 3.62-3.68 (4H, m), 5.95 (1H, s), 6.88 (2H,
J O0003246