LETTER
Lewis Acid-Promoted Transesterification
639
(3) Transesterification: ROLi, (a) Evans, D. A.; Ennis, M. D.;
Mathre, D. J. J. Am. Chem. Soc. 1982, 104, 1737. Mg(OCH3)2,
(b) Evans, D. A.; Morrissey, M. M.; Dorow, R. L. J. Am.
Chem. Soc. 1985, 107, 4346. (c) Hayashi, Y.; Narasaka, K.
Chem. Lett. 1989, 793. CH3OMgBr, (d) Evans, D. A.; Britton,
T. C.; Dorow, R. L.; Dellaria, J. F. J. Am. Chem. Soc. 1986,
108, 6395. Ti(OR)4, (e) Evans, D. A.; Ellman, J. A.; Dorow,
R. L. Tetrahedron Lett. 1987, 28, 1123. (f) Gothelf, K. V.;
Hazell, R. G.; Jørgensen, K. A. J. Org. Chem. 1996, 61, 346.
HCl (g) Tomioka, K.; Muraoka, A.; Kanai, M. J. Org. Chem.
1995, 60, 6188. LaI3, (h) Fukuzawa, S.; Hongo, Y.
thus, large amounts of the Lewis acids were required.
Both 2 and 3 provided reasonable yields while the conver-
sion with 1 was not satisfactory. It should be noted, nev-
ertheless, that no racemization was observed concomitant
with recovery of the chiral auxiliary in reasonable yields.
Table 5 Methanolysis of 4-Benzyloxazolidinone.a)
O
O
O
O
LA
Ph
N
Tetrahedron Lett. 1998, 39, 3521. LiBr/DBU, (i) Hintermann,
T.; Seebach, D.; Helv. Chim. Acta 1998, 81, 2093. Sm(OTf)3,
(j) Evans, D. A.; Coleman, P. J.; Dias, L. C. Angew. Chem. Int.
Ed. Engl. 1997, 36, 2738. Hydrolysis: LiOH/H2O,3d LiSH/
AcOOH, (k) Trimble, L. A.; Vederas, J. C. J. Am. Chem. Soc.
1986, 108, 6397. LiOOH/H2O, (l) Evans, D. A.; Britton, T. C.;
Ellman, J. C. Tetrahedron Lett. 1987, 28, 6141. LiOH/H2O2
(m) Evans, D. A.; Britton, T. C.; Ellman, J. C.; Dorow, R. L.
J. Am. Chem. Soc. 1990, 112, 4011. Reduction, LiAlH4,3a
LiBH4, (n) Evans, D. A.; Sjogren, E. B.; Bartroli, J.; Dow, R.
L. Tetrahedron Lett. 1986, 27, 4957. DBU/NaBH4, (o) Gaul,
C.; Seebach, D. Org. Lett. 2000, 2, 1501. Transamination:
MeONHMe/HCl/Me3Al, (p) Evans, D. A.; Bender, S. L.
Tetrahedron Lett. 1986, 27, 799. Thioesterification: RSLi,
(q) Damon, R. E.; Coppola, G. M. Tetrahedron Lett. 1990, 31,
2849. (r) Narasaka, K.; Saitou, M.; Iwasawa, N. Tetrahedron:
Asymmetry 1991, 2, 1305. EtSK, (s) Evans, D. A.; Brown,
Ripin, D. H.; Johnson, J. S.; Shaughnessy, E. A. Angew.
Chem. Int. Ed. Engl. 1997, 36, 2119.
O
+
Ph
OMe
HN
O
MeOH
Bn
>99 %de
Bn
>99 %ee
entry
LA (mol%)
yield (%)
of esterb)
recovery (%) of
oxazolidinoneb)
reactn time (h)
1 (0.1)
2 (0.4)
3 (3.0)
1
2
3
96
20
16
53
82
90
49
78
86
a)
Reaction Conditions: oxazolidinone 1.0 mmol; MeOH (4 mL),
85 °C.
b) Isolated yield after column chromatography.
In summary, transesterification promoted by Lewis acids
has proved to be synthetically useful. Of particular signif-
icance is the feasibility that the scope of applications can
be expanded by tuning the Lewis acidity. The catalytic ac-
tivity increased in the order: 1 < 2 < 3 whereas the
chemoselectivity in the reversed order. Finally, no need
for aqueous workup with 1 will find a wide spectrum of
utility.6
(4) (a) Otera, J.; Dan-oh, N.; Nozaki, H. J. Org. Chem. 1991, 56,
5307; J. Chem. Soc., Chem. Commun. 1991, 1742;
Tetrahedron 1993, 49, 3065. (b) Orita, A.; Mitsutome, A.;
Otera, J. J. Org. Chem. 1998, 63, 2420. (c) Orita, A.;
Sakamoto, K.; Hamada, Y.; Mitsutome, A.; Otera, J.
Tetrahedron 1999, 55, 2899. (d) Orita, A.; Sakamoto, K.;
Hamada, Y.; Otera, J. Synlett 2000, 140.
(5) Sakamoto, K.; Hamada, Y.; Akashi, H.; Orita, A.; Otera, J.
Organometallics 1999, 18, 3555. Durand, S.; Sakamoto, K.;
Fukuyama, T.; Orita, A.; Otera, J.; Duthie, A.; Dakternieks,
D.; Schulte, M.; Jurkschat, K. Organometallics 2000, 19,
3220. Sakamoto, K.; Ikeda, H.; Akashi, H.; Fukuyama, T.;
Orita, A.; Otera, J. Organometallics 2000, 19, 3242.
References and Notes
(1) Ager, D. J.; Prakash, I.; Schaad, D. R. Chem. Rev. 1996, 96,
835; Aldrichimica Acta 1997, 30, 3.
(2) For representative papers: Narasaka, K.; Inoue, M.; Okada, N.
Chem. Lett. 1986, 1109. Narasaka, K.; Yamamoto, I.
Tetrahedron 1992, 48, 5743. Corey, E. J.; Imai, N.; Zhang, H.-
Y. J. Am. Chem. Soc. 1991, 113, 728. Evans, D. A.; Miller, S.
J.; Lectka, T. J. Am. Chem. Soc. 1993, 115, 6460; Tetrahedron
Lett. 1993, 34, 7027. Evans, D. A.; Barnes, D. A. Tetrahedron
Lett. 1997, 38, 57. Evans, D. A.; Willis, M. C.; Johnston, J. N.
Org. Lett. 1999, 1, 865. Wu, J. H.; Radinov, R.; Porter, N. A.
J. Am. Chem. Soc. 1995, 117, 11029. Sibi, M. P.; Jianguo, J.
Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996,
118, 9200. Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D.
J. Org. Chem. 1997, 62, 6702.
(6) A solution of 3-cinnamoyl-1,3-oxazolidinone (217 mg,
1.0 mmol) and 1 (5.8 mg, 0.1 mmol) in toluene (0.4 mL) and
MeOH (1.6 mL) was heated at reflux under argon for 24 h.
The reaction mixture was filtered through a silica gel pad to
remove the catalyst. The filtrate was evaporated and the
residue was subjected to column chromatography on silica gel
to afford methyl cinnamate (1:9 EtOAc/hexane, 153 mg, 97%)
and 1,3-oxazolidinone (4:6 MeOH/EtOAc, 85 mg, 97%). The
reaction with 2 and 3 was carried out analogously, yet the
reaction mixture was subjected to usual aqueous workup.
Article Identifier:
1437-2096,E;2001,0,05,0637,0639,ftx,en;Y05801ST.pdf
Synlett 2001, No. 5, 637–639 ISSN 0936-5214 © Thieme Stuttgart · New York