656
D. Díez et al.
LETTER
Treatment of 1, under Sharpless conditions with L(+)- Treatment of 5 with sodium amalgam under the usual
DET gave epoxide 2 in an excellent 98% e.e. and 85% conditions2a produced 7 in 77% yield. Debenzylation un-
1
yield. The enantiomeric excess was determined by H der the same conditions as before led to 8, which was sub-
NMR after preparation of the Mosher’s ester of 2 and the mitted without purification to treatment with 6 M HCl to
Mosher’s ester6 of the racemic epoxide obtained by reac- give pyrrolidine 9 in an excellent 80% yield as its hydro-
tion with m-CPBA. A totally chemoselective epoxidation chloride salt. This compound showed the same physical
2
of the
double bond is observed in this reaction. Once properties9 as described in the literature.1c
obtained, (–)-2 was treated with p-TsCl in pyridine giving
the tosylate 3 in an 80% yield. Reaction of 3 with AlCl3 in
acetone led to 4 in a moderate 65% yield with retention of
the configuration at C-2 and inversion at C-3. In order to
check the above stereochemical assignment, compound 4
was submitted to a desulfonylation7 with samarium iodide
(Scheme 4) to give compound 4a, which has been ob-
tained previously from ribonolactone.5b
Thus, we have obtained a chiral pyrrolidine, not only
opening the way for the total synthesis of a variety of nat-
ural alkaloids,10 but also using 1-hydroxymethyl-4-sulfo-
nylbutadiene in an expeditious way that demonstrates the
versatility of this compound.
Acknowledgement
The authors thank the CICYT, Junta Castilla y Leon for financial
support (SA 44-96) and the Spanish Ministerio de Educación y Cul-
tura for a doctoral fellowship to M.T.B.
References and Notes
(1) a) Wong, C-H.; Provencher, L.; Porco jr., J. A.; Jung, S-H.;
Wang, Y-F.; Chen, L.; Wang, R. and Steensma, D. H. J. Org.
Chem. 1995, 60, 1492, b) Arribas, C.; Carreño, M. C.; Garcia
Ruano, J. L.; Rodriguez, J. F.; Santos, M. and Sanz-Tejedor,
M. A. Org. Lett. 2000, 2, 3165, c) Joubert, M.; Defoin, A.;
Tarnus, C. and Streith, J., Synlett 2000, 1366 and references
cited therein, d) O’Neil, I. A.; Cleator, E.; Hone, N.; Southern,
J. M. and Tapolczay, D. J. Synlett 2000, 1408.
(2) a) Simpkins, N.S. Sulphones in Organic Synthesis. Pergamon
Press, New York, 1993, b) Schank, K. In The Chemistry of
Sulfones and Sulfoxides; Patai, S.; Rappoport, Z., Stirling, C.,
Eds. Wiley. Chichester 1998, c) Craig, D.; Etheridge, C. J.
And Smith, A. M. Tetrahedron 1996, 52, 15267, d) Carreño,
M. C.; Urbano, A. and Di Vitta, C. Chem. Eur. J. 2000, 5, 906
and references cited therein, e) Backvall, J-E.; Chinchilla, R.;
Nájera, C. and Yus, M. Chem Rev. 1998, 98, 2291, f) Aversa,
M. C.; Baratucci, A.; Bonaccorsi, P.; Giannetto, P.
Scheme 4
As can be seen 4 is an excellent intermediate for cycliza-
tion to produce diversely substituted pyrrolidines and oth-
er heterocycles. As we had expected, treatment of 4 with
benzylamine gave 5 in 78% yield in a one pot reaction, no
other diastereoisomer being detectable from the reaction.
Finally, selective deprotection with H2, Pd/C led to 6 in
95% yield.8 The stereochemistry was assigned by a
1
study of the H NMR spectra and n.O.e experiments
(Scheme 3).
Due to problems associated with desulfonylation of 6
which proceeded in low yield, it was decided to change
the order of events for the synthesis of 9 (Scheme 5).
Tetrahedron Asymmetry 1997, 8, 1339, g) Segorbe, M. M.;
Adrio, J. and Carretero, J. C. Tetrahedron Lett. 2000, 41,
1983; h) Arce, E.; Carreño, M. C.; Cid, M. B.; García Ruano,
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Estroff, L. A.; Lafontaine, J. A.; Montero, C.; McCulley, D. J.;
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Pradilla, R.; Castro, S.; Dorado, R.; Morente, M. J. Org.
Chem. 1997, 62, 6326, j) Urones, J. G.; Marcos, I. S.; Garrido,
N. M.; Basabe, P.; Bastida, A. J.; San Feliciano, S. G.; Díez,
D. and Goodman J. M. Synlett 1998, 1361.
(3) Urones, J. G.; Marcos, I. S.; Garrido, N. M.; Basabe, P.; San
Feliciano, S. G.; Coca, R. and Díez, D. Synlett 1998, 1364.
(4) a) Marta, R. P.; Afonso, C. A. M.; McCarvey, T.; Lee, P. and
Batey, R. A. Tetrahedron Lett. 1998 40, 9189, b) Wang, Q.;
Sasaki, N. A. and Potier, P. Tetrahedron 1998, 54, 15759,
c) Delair, P.; Brot, E.; Kanazawa, A. and Greene, A. E. J. Org.
Chem. 1999, 64, 1383.
(5) a) Wershofen, S. and Scharf, H-D. Synthesis 1988, 854,
b) Jager, V. and Hafele, B. Synthesis 1987, 801.
(6) Preparation of the (R)-MPTA ester derivative and subsequent
N.M.R. analysis at 400 MHz showed the optical purity to be
95%ee. See: Dale, J. A.; Dull, D. L. and Mosher, H. S. J. Org.
Chem. 1969, 34, 2543.
(7) D.e 93% by comparison with 4a in reference 5b [ ]D21 = -44.5
(c 1.87, CHCl3); Keck, G. E.; Savin, K. A. and Weglarz, M. A.
J. Org. Chem. 1995, 60, 3194
Scheme 5 a) Na(Hg), MeOH, 77%; b) H2, Pd/C, MeOH, 90%; c)
HCl 6 M, MeOH, 80%
Synlett 2001, No. 5, 655–657 ISSN 0936-5214 © Thieme Stuttgart · New York