8
40
J. M. Concellón et al.
LETTER
(
3) For a review of synthetic applications of a,b-unsaturated
ketones, see: (a) Patai, S.; Rappoport, Z. In The Chemistry of
Enones; John Wiley and Sons: New York, 1989, 281–312.
1,1-dichloroketone (0.5 mmol, 1 equiv) and the correspond-
ing aldehyde (0.5 mmol, 1 equiv) in THF (2 mL) under
nitrogen atmosphere. The reaction was refluxed for 2 h, and
then the reaction was quenched by the addition of 1.0 M aq
HCl. Standard workup afforded the crude a,b-enones 3
which were purified by flash column chromatography on
silica gel (hexane–EtOAc, 10:1), or alternatively filtered
(
b) For recent synthetic applications of a,b-unsaturated
ketones, see: Zhenghong, Z.; Yilong, T.; Lixin, W.;
Guofeng, Z.; Qilin, Z.; Chuchi, T. Synth. Commun. 2004, 34,
1359.
®
(
4) For a recent review of synthesis of a,b-unsaturated ketones,
see: Foster, C. E.; Mackie, P. R. In Comprehensive Organic
Functional Group Transformations II; Katrizky, A. R.;
Taylor, R. J. K., Eds.; Elsevier, Ltd.: Oxford, 2005, 215–
through a pad of Celite . When FeCl ·6H O (0.06 equiv)
3
2
was required, this salt was added to the 1,1-dichloroketone
(1 equiv) and the corresponding aldehyde (1 equiv) in THF
prior to SmI (6 equiv) addition.
2
2
66.
(15) When the minor diastereomer was not detected E/Z ratio was
assigned >98:2.
(16) The coupling constant between the olefinic protons of
compounds 3 ranging between J = 16.2 and 14.1 Hz were in
accordance with the average literature values: Silverstein, R.
M.; Bassler, G. C.; Morrill, T. C. Spectrometric
(
5) (a) Mulzer, J.; Sieg, A.; Bruecher, C.; Mueller, D.; Martin,
H. J. Synlett 2005, 685. (b) Sano, S.; Yokoyama, K.; Shiro,
M.; Nagao, Y. Chem. Pharm. Bull. 2002, 50, 706.
(
(
c) Snider, B. B.; Shi, B. Tetrahedron Lett. 2001, 42, 9123.
d) Lee, H. K.; Kim, E.-K.; Pak, C. S. Tetrahedron Lett.
2
002, 43, 9641. (e) Maryanoff, B. E.; Reitz, A. B. Chem.
Identification of Organic Compounds; John Wiley and Sons:
New York, 1991, Chap. 4, App. F, 221.
Rev. 1989, 89, 863.
(
6) (a) Shibuya, M.; Ito, S.; Takahashi, M.; Iwabuchi, Y. Org.
Lett. 2004, 6, 4303. (b) Jurado-González, M.; Sullivan, A.
C.; Wilson, J. R. Tetrahedron Lett. 2004, 45, 4465.
(17) Trost, B. M.; Parquette, J. R. J. Org. Chem. 1993, 58, 1579.
(18) (a) Machrouhi, F.; Hamann, B.; Namy, J.-L.; Kagan, H. B.
Synlett 1996, 633. (b) Molander, G. A.; Harris, C. R. J. Am.
Chem. Soc. 1995, 117, 3705. (c) Molander, G. A.; McKie, J.
A. J. Org. Chem. 1991, 56, 4112.
(
c) Bora, U.; Chaudhuri, M. K.; Dey, D.; Kalita, D.;
Kharmawphlang, W.; Mandal, G. C. Tetrahedron 2001, 57,
2
445. (d) Pelter, A.; Colclough, M. E. Tetrahedron Lett.
(19) The catalytic effect of FeCl could be related to its ability to
3
+
2
+3
1986, 27, 1935.
catalyze formation of ketyl radicals and/or Sm /Sm
(
7) (a) Kim, J. H.; Lim, H. J.; Cheon, S. H. Tetrahedron 2003,
conversion: Girard, P.; Namy, J.-L.; Kagan, H. B. J. Am.
Chem. Soc. 1980, 102, 2693; and references cited therein.
(20) (a) For compounds 3d and 3g, see: Kourouli, T.; Kefalas, P.;
Ragoussis, N.; Ragoussis, V. J. Org. Chem. 2002, 67, 4615.
(b) For compound 3f, see: Fayos, J.; Clardy, J.; Dolby, L. J.;
Farnham, T. J. Org. Chem. 1977, 42, 1349. (c) For
compounds 3e and 3l, see: Heathcock, C. H.; Uehling, D. E.
J. Org. Chem. 1986, 51, 279. (d) For compound (E)-3h, see:
Nakano, T.; Ishii, Y.; Ogawa, M. J. Org. Chem. 1987, 52,
4855.
59, 7501. (b) Tachihara, T.; Kitahara, T. Tetrahedron 2003,
59, 1773. (c) Clive, D.; Stephen, P. Chem. Commun. 2002,
1940. (d) Schwarz, I.; Braun, M. Chem. Eur. J. 1999, 5,
2300. (e) Taber, D. F.; Herr, R. J.; Pack, S. K.; Geremia, J.
M. J. Org. Chem. 1996, 61, 2908.
(
8) (a) Figadere, B.; Franck, X. Science of Synthesis, Vol. 26;
Thieme: Stuttgart, 2005, 401–411. (b) Hermanson, J. R.;
Hershberger, J. W.; Pinhas, A. R. Organometallics 1995, 14,
5426.
(
9) (a) Xi, Z.; Fan, H.-T.; Mito, S.; Takahashi, T. J. Organomet.
Chem. 2003, 682, 108. (b) Deshong, P.; Sidler, D. R.
Tetrahedron Lett. 1987, 28, 2233.
(21) An alternative mechanism to explain the olefination of
aldehydes by reaction of gem-dihalogenated compounds in
the presence of CrCl and based on the formation of gem-
2
(
(
(
(
10) Concellón, J. M.; Huerta, M. Tetrahedron Lett. 2003, 44,
931.
11) Concellón, J. M.; Rodríguez-Solla, H.; Méjica, C.
Tetrahedron Lett. 2004, 45, 2977.
dimetallic reagents has been previously proposed: Okazoe,
T.; Takai, K.; Utimoto, K. J. Am. Chem. Soc. 1987, 109, 951.
(22) A similar transition-state model involving a chair transition
state was proposed to explain the selectivity in other
1
12) Concellón, J. M.; Concellón, C.; Méjica, C. J. Org. Chem.
reactions of SmI : (a) Molander, G. A.; Etter, J. B.; Zinke, P.
2
2005, 70, 6111.
W. J. Am. Chem. Soc. 1987, 109, 453. (b) Urban, D.;
Skrydstrup, T.; Beau, J. M. J. Org. Chem. 1998, 63, 2507.
(c) Enemaerke, R. J.; Larsen, J.; Hjollund, G. H.; Skrydstrup,
T.; Daasbjerg, K. Organometallics 2005, 24, 1252.
(d) Davis, T. A.; Chopade, P. R.; Hilmersson, G.; Flowers,
R. A. Org. Lett. 2005, 7, 119. (e) To see similar chair
13) The solution of SmI in THF was rapidly obtained by
2
reaction of diiodomethane with samarium powder in the
presence of sonic waves: Concellón, J. M.; Rodríguez-Solla,
H.; Bardales, E.; Huerta, M. Eur. J. Org. Chem. 2003, 1775.
14) General Procedure for the Synthesis of Compounds 3
SmI (3 mmol, 6 equiv) in THF (30 mL), or CrCl (3 mmol,
(
transition states in the reaction with CrCl , see ref. 11 and
2
2
2
6
equiv) in THF (13 mL), was added to a stirred solution of
12.
Synlett 2006, No. 6, 837–840 © Thieme Stuttgart · New York