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R. Mello et al.
LETTER
Acknowledgment
Financial support from the Spanish Dirección General de Inves-
tigación (BQU2003-00315) and Generalitat Valenciana (Grupos
2006, GV06/217) is acknowledged. We thank S.C.S.I.E. (UV) for
access to their instrumental facilities.
References
(1) (a) Adam, W.; Curci, R.; Edwards, J. O. Acc. Chem. Res.
1989, 22, 205. (b) Murray, R. W. Chem. Rev. 1989, 89,
1187. (c) Curci, R. In Advances in Oxygenated Processes
1990, 2, 1. (d) Adam, W.; Hadjiaropoglou, L.; Curci, R.;
Mello, R. In Organic Peroxides; Wiley: Chichester, 1992,
195–219. (e) Clennan, E. L. Trends Org. Chem. 1995, 5,
231. (f) Adam, W.; Smerz, A. K. Bull. Soc. Chim. Belg.
1996, 105, 581. (g) Peroxide Chemistry; Adam, W., Ed.;
Wiley-VCH: Weinheim, 2000. (h) Adam, W.; Saha-Möller,
C. R.; Ganeshpure, P. A. Chem. Rev. 2001, 101, 3499.
(2) (a) Mello, R.; Fiorentino, M.; Fusco, C.; Curci, R. J. Am.
Chem. Soc. 1989, 111, 6749. (b) Mello, R.; Cassidei, L.;
Fiorentino, M.; Fusco, C.; Hümmer, W.; Jäger, V.; Curci, R.
J. Am. Chem. Soc. 1991, 113, 2205. (c) Curci, R.;
D’Accolti, L.; Fiorentino, M.; Fusco, C.; Adam, W.;
González-Núñez, M. E.; Mello, R. Tetrahedron Lett. 1992,
33, 4225. (d) Bovicelli, P.; Lupattelli, P.; Mincione, E.;
Prencipe, T.; Curci, R. J. Org. Chem. 1992, 57, 5052.
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Curci, R. J. Am. Chem. Soc. 1994, 116, 2375. (g) Asensio,
G.; Mello, R.; González-Núñez, M. E.; Castellano, G.;
Corral, J. Angew. Chem., Int. Ed. Engl. 1996, 35, 217.
(h) Asensio, G.; Castellano, G.; Mello, R.; González-Núñez,
M. E. J. Org. Chem. 1996, 61, 5564. (i) Curci, R.;
Detomaso, A.; Lattanzio, M. E.; Carpenter, G. B. J. Am.
Chem. Soc. 1996, 118, 11089. (j) Fusco, C.; Fiorentino, M.;
Dinoi, A.; Curci, R. J. Org. Chem. 1996, 61, 8681.
(k) D’Accolti, L.; Dinoi, A.; Fusco, C.; Russo, A.; Curci, R.
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Annese, C.; Rella, M. R.; Turteltaub, J. S.; Williard, P. G.;
Curci, R. J. Org. Chem. 2004, 69, 8510. (m) González-
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2001, 123, 7487.
Figure 1 Schematic view of the reaction apparatus. A: Syringe
pump; B: polypropylene syringe charged with aq Oxone®; C: PTFE
needle; D: thermometer; E: water bath; F: magnetic stirrer; G: reac-
tion zone 1; H: polypropylene tubing connected to a glass tube with
porous end; I: reaction zone 2; J: cooling bath.
B) Reaction Zone 2
A 250 mL Schlenk tube was charged with 50 mL of a 0.1 M CH2Cl2
solution of 5-a-cholestan-2-one (5 mmol) and cooled to –15 °C with
a salt-ice bath. The outlet of reaction zone 1 was connected to a
glass tube with a porous end, which was dipped into the substrate
solution. The Schlenk tube was filled with 5 mm diameter glass
beads and the outlet was connected to an additional trap charged
with a 1 M CH2Cl2 solution of phenylmethylsulfide.
(3) Mello, R.; Fiorentino, M.; Sciacovelli, O.; Curci, R. J. Org.
Chem. 1988, 53, 3890.
(4) (a) Yang, D.; Yip, Y.-C.; Wang, X.-C. Tetrahedron Lett.
1997, 38, 7083. (b) Bols, M.; Haezel, R. G.; Thomsen, I. B.
Chem. Eur. J. 1997, 3, 940. (c) Yang, D.; Wong, M.-K.;
Yip, Y.-C. J. Org. Chem. 1995, 60, 3887.
(5) (a) Montgomery, R. E. J. Am. Chem. Soc. 1974, 96, 7820.
(b) Edwards, J. O.; Pater, R. H.; Curci, R.; Di Furia, F.
Photochem. Photobiol. 1979, 30, 63. (c) Curci, R.;
Fiorentino, M.; Troisi, L.; Edwards, J. O.; Pater, R. H. J.
Org. Chem. 1980, 45, 4758. (d) Gallopo, A. R.; Edwards, J.
O. J. Org. Chem. 1981, 46, 1684.
(6) (a) Ball, D. L.; Edwards, J. O. J. Am. Chem. Soc. 1956, 78,
1125. (b) Goodman, J. F.; Robson, P. J. Chem. Soc. 1963,
2871.
(7) Adam, W.; Curci, R.; González-Núñez, M. E.; Mello, R. J.
Am. Chem. Soc. 1991, 113, 7654.
C) Oxidation Reaction
Addition of the aq caroate solution at reaction zone 1 started the
generation of dioxirane 1a, which bubbled gently through the reac-
tor containing the substrate. The syringe was refilled 3 times to give
200 mL of the aq caroate solution. The progress of the reaction was
monitored by taking samples from the substrate solution at reaction
zone 2 and analyzing them by gas-liquid chromatography. After
200 mL of the aq caroate solution was added, the reactor for the
generation of dioxirane 1 was charged with an additional 100 g of
NaHCO3. The system was closed again and an additional 200 mL of
2 M aq solution of caroate was added.
The generation of dioxirane 1a was repeated as described until a to-
tal of 1400 mL of a 2 M aq solution of caroate was added. GC-MS
analysis of the substrate solution at reaction zone 2 indicated an
80% conversion of the substrate. Products2d were recovered by
collecting the solution from the reactor and evaporating the solvent
under vacuum.
(8) Gambaryan, N. P.; Rokhlin, E. M.; Zeifman, Y. V.; Ching-
Yub, C.; Knunyants, I. L. Angew. Chem., Int. Ed. Engl.
1966, 5, 947.
(9) González-Núñez, M. E.; Mello, R.; Olmos, A.; Asensio, G.
J. Org. Chem. 2005, 70, 10879.
Synlett 2007, No. 1, 47–50 © Thieme Stuttgart · New York