3964 J . Org. Chem., Vol. 65, No. 13, 2000
Degueil-Castaing et al.
by NMR by following the disappearance of the peroxyacetal.
The solvent was evaporated under vacuum, and the product
was isolated by flash chromatography or distilled.
In itia tion by th e Th er m a l Decom p osition of a n In itia -
tor . The mixture of peroxyacetal, “transfer agent”, initiator,
and solvent was heated for 12 h at 80 °C (for AIBN and Bz2O2)
or 110 °C (for DMEPA) in a glass autoclave.
The solvent was evaporated after the reaction under vacuum,
and the product was isolated by flash chromatography or
distilled. When the reaction product was known it was
identified by comparison with an authentic sample (NMR and
GC); unknown ones were characterized by 1H and 13C NMR
and microanalysis.
P r od u cts. Ch lor oa lk a n es: peroxyacetal (P 1 or P 2, 10
mmol), carbon tetrachloride (50 mmol), BEt3/O2. Eluant:
petroleum ether. Ch lor ou n d eca n e23 (1a ): 86%. 2-Ch lor o-
u n d eca n e24 (1b): 75%.
Br om oa lk a n es: peroxyacetal (P 1 or P 2, 10 mmol), bromo-
trichloromethane (11 mmol), trichloromethane (50 mmol),
BEt3/O2. Eluant: petroleum ether. Br om ou n d eca n e25 (1c):
75%. 2-Br om ou n d eca n e24 (1d ): 75%.
nitriles, 2-alkyl-3-chloromaleic anhydrides, 1-phenyl-
alkynes, and ethyl 2-alkylpropenoates in 40-86% yield
under mild conditions.
Exp er im en ta l Section
Gen er a l P r oced u r e a n d Ma ter ia ls. 1H NMR spectra were
recorded at 250 or 200 MHz, and the 13C NMR data were
obtained at 62.9 or 50.3 MHz. The solvent was CDCl3, and
chemical shifts are reported relative to tetramethylsilane; J
values are quoted in Hz. GC was performed with a silica
capillary column DB5 (25 m by 0.3 mm by 1.5 µm) on a Varian
3300 apparatus. Microanalysis were performed by CNRS,
Vernaison, France. Flash column chromatographic purifica-
tions were carried out on SDS silica gel (200-400 mesh) and
monitored by TLC using Schleider and Schuell precoated silica
gel F1500/LS254 (0.25 mm thickness) plastic-backed plates.
The plates were visualized under UV or iodine vapor. Mixtures
of light petroleum ether (bp 45-55 °C) and diethyl ether were
used as eluant. Other types of purifications were performed
by a bulb-to-bulb distillation under reduced pressure using a
Bu¨chi oven. Benzene was dried over sodium. Dodecanal and
2-methylundecanal were purchased from Aldrich and were
redistilled before use. The other products were commercially
available and used without any further purification. R,R′-
Azobisisobutyronitrile was obtained from Fluka. Solution (1
M) of triethylborane in hexanes, benzoyl peroxide (Bz2O2),
cyanogen bromide, and dichloromaleic anhydride were pur-
chased from Aldrich.
Methyl iodoacetate,17 methyl (ethoxythiocarbonyl)thioethan-
oate,18 ethyl 2-bromomethylpropenoate,19 1,1-dimethylethyl-
peracetate,20 phenyltrifluoromethylsulfonylethyne,21 and 7,7-
dimethyl-2-(3-formylpropyl)bicyclo[3.1.1]hept-2-ene22 were
obtained according literature methods.
P r ep a r a t ion of P er oxya cet a ls. They were synthesized
from a dimethylacetal and 1,1-dimethyl-prop-2-enylhydroper-
oxide3 with a catalytic amount of PTSA using the method
described by Colombani and Maillard2 and used with no
further purification.
Iod oa lk a n es: peroxyacetal (P 1 or P 2, 10 mmol), ethyl
iodoacetate (11 mmol), cyclohexane (50 mmol), BEt3/O2. Elu-
ant: petroleum ether. Iod ou n d eca n e25 (1e): 75%. 2-Iod ou n -
d eca n e24 (1f): 75%.
Alk a n es. Rea ction a t r oom tem p er a tu r e: peroxyacetal
(P 1 or P 2, 10 mmol), dodecanethiol (11 mmol), cyclohexane
(50 mmol), BEt3/O2. Eluant: petroleum ether. Un d eca n e25
(1i): 75%.
Rea ction a t 80 °C: peroxyacetal (P 3, 10 mmol), dodecane-
thiol (11 mmol), cyclohexane (50 mmol), and benzoyl peroxide
(1 mmol). Eluant: petroleum ether.
7,7-Dim eth yl-2-pr opylbicyclo[3.1.1]h ept-2-en e (1t): 75%;
1H NMR δ 5.2 (s, 1H), 2.4-1.9 and 1.5-1.3 (m, 10H), 1.3 (s,
3H), 0.9 (t, J ) 7 Hz, 3H), 0.9 (s, 3H); 13C NMR δ 148.5, 115.7,
45.8, 41.0, 39.2, 37.9, 31.7, 31.3, 26.4, 21.2, 20.4, 14.0. Anal.
Calcd for C12H20: C, 87.73; H, 12.27. Found: C, 87.40; H, 12.40.
Xa n th a tes: peroxyacetal (P 1 or P 2, 10 mmol), methyl-
(ethoxythiocarbonyl)thioethanoate (2g, 11 mmol), cyclohexane
(50 mmol), BEt3/O2. Eluant: 80% of petroleum ether-20% of
diethyl ether.
2,3-Dim et h yl-2-(1-m et h oxyd od ecyl)p er oxyb u t -3-en e
1
(P 1): 80%; H NMR δ 4.88 (s, 1H), 4.8 (s, 1H), 4.72 (t, J ) 6
O-Eth yl u n d ecylsu lfa n ylca r both ioa te (1g): 75%; 1H
NMR δ 4.56 (q, J ) 7.1 Hz, 2H), 3.03 (t, J ) 7.4 Hz, 2H), 1.74-
1.02 (m, 21H), 0.8 (t, J ) 6.2 Hz, 3 H); 13C NMR δ 215.0, 69.6,
35.9, 31.9, 29.6, 29.5, 29.4, 29.2, 28.9, 28.4, 22.7, 14.1, 13.8.
Anal. Calcd for C14H28OS2: C, 60.81; H, 10.21; S, 23.19.
Found: C, 60.73; H, 10.04; S, 23.25.
Hz, 1H), 3.4 (s, 3H), 1.76 (s, 3H), 1.6-1 (m, 26H), 0.8 (t, J )
6 Hz, 3H); 13C NMR δ 148.8, 111.1, 107.4, 83.2, 55.8, 31.9, 29.7,
29.6, 29.5, 29.4, 29.3, 24.9, 24.5, 22.7, 18.6, 18.5, 14.1.
2,3-Dim eth yl-2-(1-m eth oxy-2-m eth ylu n decyl)per oxybu t-
1
3-en e (P 2): 80%; H NMR δ 4.9 (s, 1H), 4.8 (s, 1H), 4.56 and
4.52 (d, J ) 6 Hz, 1H), 3.52 (s, 3H), 1.8 (s, 3H), 1.6-1 (m, 23H),
0.88 (d, J ) 6 Hz, 3H), 0;84 (t, J ) 6 Hz, 3H); 13C NMR δ
148.7, 111.1, 110.6, 110.4, 83.3, 57.3, 57.2, 36.2, 36.1, 32.1, 32.0,
31.9, 29.8, 29.6, 29.4, 27.0, 26.9, 24.5, 24.4, 22.7, 18.6, 14.9,
14.5, 14.1.
1
O-Eth yl 2-u n d ecylsu lfa n ylca r both ioa te (1h ): 75%; H
NMR δ 4.56 (q, J ) 7 Hz, 2H), 3.64 (sx, J ) 7 Hz, 1H), 1.7-
1.1 (m, 22H), 0.8 (t, J ) 6.2 Hz, 3H); 13C NMR δ 214.8, 69.5,
46.0, 36.0, 32.0, 29.6, 29.5, 29.4, 27.1, 22.8, 20.6, 14.2, 13.9.
Anal. Calcd for C14H28OS2: C, 60.81; H, 10.21; S, 23.19.
Found: C, 60.36; H, 10.27; S, 23.27.
E t h yl 2-a lk ylp r op en oa t es: peroxyacetal (P 1 or P 2, 10
mmol), ethyl 2-bromomethylpropenoate (2k , 12 mmol), cyclo-
hexane (60 mmol), AIBN (1.2 mmol).
7,7-Dim et h yl-2-[4-m et h oxy-4-(1,1,2-t r im et h ylp r op -2-
1
en yl)p er oxybu tyl]bicyclo[3.1.1]h ep t-2-en e (P 3): 70%; H
NMR δ 5.1 (s, 1H), 4.9 (s, 1H), 4.8 (s, 1H), 4.7 (t, J ) 6 Hz,
1H), 3.4 (s, 3H), 2.4-1.8 and 1.6-1.3 (m, 12H), 1.8 (s, 3H), 1.3
(s, 6H), 1.2 (s, 3H), 0.8 (s, 3H); 13C NMR δ 148.7, 147.9, 116.1,
111.2, 107.3, 107.2, 83.2, 55.9, 55.8, 45.6, 40.8, 37.9, 36.5, 31.7,
31.6, 31.2, 29.0, 26.3, 24.5, 22.1, 18.6.
Gen er a l P r oced u r es for th e In d u ced Decom p osition
of th e P er oxya ceta ls. - BEt3/O2 In itia tin g System . A 1 M
solution of triethyborane in hexanes was added dropwise at
Eth yl 2-d od ecylp r op en oa te (1k ): 60% (lit.26); eluant:
petroleum ether 94%-diethyl ether 6%; 1H NMR δ 6.0 (s, 1H),
5.4 (s, 1H), 4.1 (q, J ) 8 Hz, 2H), 2.2 (t, J ) 7 Hz, 2H), 1.5-
1.1 (m, 23H), 0.8 (t, J ) 7 Hz, 3H); 13C NMR δ 166.9, 140.8,
123.7, 60.1, 31.6, 31.5, 29.4, 29.3, 29.1, 29.0, 28.9, 28.1, 22.3,
13.8, 13.7.
room temperature directly in
a mixture of peroxyacetal,
Eth yl 2-(2-m eth ylu n d ecyl)p r op en oa te (1l): 60%; elu-
“transfer agent”, and the solvent. The reaction was monitored
1
ant: petroleum ether 95%-diethyl ether 5%; H NMR δ 6.1
(s, 1H), 5.4 (s, 1H), 4.1 (q, J ) 7.1 Hz, 2H), 2.32-2.25 (m, 1H),
1.98-1.9 (m, 1H), 1.9-1.6 (m, 1H), 1.42-1.1 (m, 19H), 0.8 (t,
J ) 6.6 Hz, 3H), 0.76 (d, J ) 6.6 Hz, 3H); 13C NMR δ 167.2,
140.0, 125.2, 60.3, 36.8, 31.8, 29.9, 29.7, 29.6, 29.3, 27.0, 22.6,
(17) Furniss, B. S.; Hannaford, A. J .; Rogers, V.; Smith, P. W. G.;
Tatchell, A. R. Vogel’s text book of practical chemistry, 4th ed.; Longman
scientific and technical edit.: New York, 1978; p 1087.
(18) Le Minor, A.; Kanjo, I. E.; Villemin, D. Polym. Bull. 1989, 21,
445-448.
(19) Villieras, J .; Rambaud, M. Synthesis 1982, 924-926.
(20) Bartlett, P. D.; Hiatt, R. R. J . Am. Chem. Soc. 1958, 80, 1398.
(21) Hanack, M.; Wilhelm, B.; Subramanian, L. R. Synthesis 1988,
592-595.
(22) Kruck, C.; Velzen, J . C.; De Boer, T. J . Recl. Trav. Chim. 1969,
139-148.
(23) Carrington, R. A. G.; Evans, H. C. J . Chem. Soc. 1957, 1701-
1709.
(24) Houben, J .; Boedler, J .; Fischer, W. Ber. 1936, 69B, 1766-1788.
(25) Commercially available.
(26) Hayashi, K.; Nunami, K.; Sakai, K.; Ozaki, K.; Kato, J .; Kirashi,
K.; Yoneda, N. Chem. Pharm. Bull. 1985, 33, 2011-2022.