SCHEME 1
SCHEME 2
Enantioselective Synthesis of
γ-Aryl-γ-butyrolactones by Sequential
Asymmetric Epoxidation, Ring Expansion, and
Baeyer-Villiger Oxidation
Bin Wang, Yu-Mei Shen, and Yian Shi*
Department of Chemistry, Colorado State UniVersity, Fort
Collins, Colorado 80523
ReceiVed June 28, 2006
SCHEME 3
The low ee values obtained for this class of olefin are likely
due to a significant competition from planar transition state B
(Scheme 2).6 Our studies on N-aryl-substituted oxazolidinone-
containing ketones have shown that there is an attractive
interaction between the aryl group of the olefin and the
oxazolidinone moiety of the ketone catalyst,7,8 which should
favor the desired spiro transition state C over a competing planar
transition state such as D (Scheme 3). This has already been
observed in the case of benzylidenecyclobutane derivatives,9
so higher ee values should be expected for benzylidenecyclo-
propane derivatives with ketone 610 than with ketone 5.
This paper describes an enantioselective synthesis of γ-bu-
tyrolactones, using the N-tolyl-substituted oxazolidinone-
containing ketone as catalyst and Oxone as oxidant via a
sequential asymmetric epoxidation of benzylidenecyclopro-
panes, ring expansion, and Baeyer-Villiger oxidation. Up
to 91% ee was obtained. Optically active cyclobutanones can
also be obtained by suppressing the Baeyer-Villiger oxida-
tion with use of more ketone catalyst and less Oxone.
(3) For leading references on the rearrangement of oxaspiropentanes and
oxaspirohexanes, see: (a) Trost, B. M.; Bogdanowicz, M. J. J. Am. Chem.
Soc. 1972, 94, 4777. (b) Trost, B. M.; Bogdanowicz, M. J. J. Am. Chem.
Soc. 1973, 95, 5321. (c) Trost, B. M.; Scudder, P. H. J. Am. Chem. Soc.
1977, 99, 7601. (d) Crandall, J. K.; Conover, W. W. J. Org. Chem. 1978,
43, 3533.
Optically active γ-butyrolactones are a useful class of chiral
building blocks for the synthesis of biologically important
molecules. A number of methods have been reported for the
preparation of chiral γ-lactones.1 Earlier, Ihara and co-workers2
reported that chiral γ-aryl-γ-butyrolactones were obtained in
37% to 72% ee by asymmetric epoxidation of trisubstituted
benzylidenecyclopropane derivatives (R ) H) using fructose-
derived ketone 5 and Oxone, followed by in situ epoxide
rearrangement and Baeyer-Villiger oxidation (Schemes 1 and
2).3-5
(4) For leading references on asymmetric epoxidation of cyclopropy-
lideneethanol and subsequent rearrangement, see: (a) Nemoto, H.; Ishibashi,
H.; Nagamochi, M.; Fukumoto, K. J. Org. Chem. 1992, 57, 1707. (b) Nemo-
to, H.; Shiraki, M.; Nagamochi, M.; Fukumoto, K. Tetrahedron Lett. 1993,
34, 4939. (c) Nemoto, H.; Nagamochi, M.; Ishibashi, H.; Fukumoto, K. J.
Org. Chem. 1994, 59, 74. (d) Nemoto, H.; Tanabe, T.; Fukumoto, K. J. Org.
Chem. 1995, 60, 6785. (e) Nemoto, H.; Fukumoto, K. Synlett 1997, 863.
(5) For leading references on asymmetric dihydroxylation of cyclopro-
pylidene derivatives and subsequent rearrangement, see: (a) Krief, A.;
Ronvaux, A.; Tuch, A. Bull. Soc. Chim. Belg. 1997, 106, 699. (b) Krief,
A.; Ronvaux, A.; Tuch, A. Tetrahedron 1998, 54, 6903. (c) Nemoto, H.;
Miyata, J.; Hakamata, H.; Fukumoto, K. Tetrahedron Lett. 1995, 36, 1055.
(d) Nemoto, H.; Miyata, J.; Hakamata, H.; Nagamochi, M.; Fukumoto, K.
Tetrahedron 1995, 51, 5511. (e) Diffendal, J. M.; Filan, J.; Spoors, P. G.
Tetrahedron Lett. 1999, 40, 6137. (f) Miyata, J.; Nemoto, H.; Ihara, M. J.
Org. Chem. 2000, 65, 504.
(6) Wang, Z.-X.; Tu, Y.; Frohn, M.; Zhang, J.-R.; Shi, Y. J. Am. Chem.
Soc. 1997, 119, 11224.
(7) (a) Tian, H.; She, X.; Shu, L.; Yu, H.; Shi, Y. J. Am. Chem. Soc.
2000, 122, 11551. (b) Tian, H.; She, X.; Yu, H.; Shu, L.; Shi, Y. J. Org.
Chem. 2002, 67, 2435.
(8) (a) Shu, L.; Wang, P.; Gan, Y.; Shi, Y. Org. Lett. 2003, 5, 293. (b)
Shu, L.; Shi, Y. Tetrahedron Lett. 2004, 45, 8115. (c) Goeddel, D.; Shu,
L.; Yuan, Y.; Wong, O. A.; Wang, B.; Shi, Y. J. Org. Chem. 2006, 71,
1715. (d) Wong, O. A.; Shi, Y. J. Org. Chem. 2006, 71, 3973.
(1) For examples on the synthesis of optically active γ-butyrolactones,
see: (a) Gutman, A. L.; Zuobi, K.; Bravdo, T. J. Org. Chem. 1990, 55,
3546. (b) Brown, H. C.; Kulkarni, S. V.; Racherla, U. S. J. Org. Chem.
1994, 59, 365. (c) Nair, V.; Prabhakaran, J. J. Chem. Soc., Perkin Trans. 1
1996, 593. (d) Nair, V.; Prabhakaran, J.; George, T. G. Tetrahedron 1997,
53, 15061. (e) Fukuzawa, S-I.; Seki, K.; Tatsuzawa, M.; Mutoh, K. J. Am.
Chem. Soc. 1997, 119, 1482. (f) Mikami, K.; Yamaoka, M. Tetrahedron
Lett. 1998, 39, 4501. (g) Merlic, C. A.; Walsh, J. C. J. Org. Chem. 2001,
66, 2265. (h) Ramachandran, P. V.; Pitre, S.; Brown, H. C. J. Org. Chem.
2002, 67, 5315. (i) Movassaghi, M.; Jacobsen, E. N. J. Am. Chem. Soc.
2002, 124, 2456. (j) Kamal, A.; Sandbhor, M.; Shaik, A. Tetrahedron:
Asymmetry 2003, 14, 1575.
(2) (a) Yoshida, M.; Ismail, M. A-H.; Nemoto, H.; Ihara, M. Heterocycles
1999, 50, 673. (b) Yoshida, M.; Ismail, M. A-H.; Nemoto, H.; Ihara, M. J.
Chem. Soc., Perkin Trans. 1 2000, 2629.
10.1021/jo061341j CCC: $33.50 © 2006 American Chemical Society
Published on Web 11/11/2006
J. Org. Chem. 2006, 71, 9519-9521
9519