HCl. It was extracted with CH2Cl2, the organic layer was dried
over anhydrous MgSO4 and concentrated. Flash chromato-
graphy of the residue (benzene–ethyl ether–hexane 2 : 1 : 6) gave
the chlorohydrin (347 mg, 88%) and acetophenone (9.5 mg, 4%).
δH(300 MHz; CDCl3) 7.37 (m, 5H, ArH), 5.61 (m, 1H,
to the reaction mixture and it was washed with H2O. The
organic layer was dried and concentrated to give the epoxide
(60 mg, 79%). δH(300 MHz; CDCl3) 7.3 (m, 5H, ArH), 5.75 (m,
1H, CH ᎐CH-), 5.16 (t, 2H, CH ᎐CH-), 3.11 (q, 1H, CH OC),
᎐
᎐
2
2
2
2.84 (q, 1H, CH ᎐CHCH -), 2.51 (q, 1H, CH ᎐CHCH -), 0.99
᎐
2
᎐
2
2
2
CH ᎐CHCH -), 5.15 (t, 2H, CH ᎐CHCH -), 3.85 (dd, J = 3.9,
(d, 3H, CH3CHCl).
᎐
᎐
2
2
2
2
9.1 Hz, 2H, -CH Cl), 2.71 (d, J = 7.5 Hz, 2H, CH ᎐CHCH -),
2.45 (s, 1H, -OH).
᎐
2
2
2
Method C. The chlorohydrin (from bromide A and entry 4 in
Table 1, 142 mg, 0.5 mmol) was dissolved in acetone and K2CO3
(110 mg, 0.8 mmol) was added. The resulting solution was at
room temperature for 2.5 h. The reaction mixture was extracted
with CH2Cl2. The organic layer was dried and concentrated to
give the epoxide (107 mg, 87%). δH(300 MHz; CDCl3) 7.35 (m,
5H, ArH), 5.73 (m, 1H, CH ᎐CHCH -), 5.09 (t, 2H, CH ᎐
Method B. To a solution of ethyl 2-chloro-3-oxo-3-phenyl-
propanoate (340 mg, 1.5 mmol) in 25% aq. THF (5 mL) were
added allyl bromide (195 µL, 2.3 mmol) and indium powder
(207 mg, 1.8 mmol). The solution was stirred at room temper-
ature for 7 h. The reaction mixture was quenched with 6 M
HCl, then was extracted with CH2Cl2. The organic layer was
dried over anhydrous MgSO4 and concentrated. Flash chrom-
atography of the residue (hexane–ethyl acetate 20 : 1) gave the
chlorohydrin (313 mg, 78%). δH(300 MHz; CDCl3) 7.42–7.27
᎐
᎐
2
2
2
CHCH2-), 4.3 (m, 2H, -OCH2CH3), 3.5 (s, 1H, COCH), 2.92
(dd, J = 7.1, 15.1 Hz, 1H, CH ᎐CHCH -), 2.78 (dd, J = 7.1, 15.1
᎐
2
2
Hz, 1H, CH ᎐CHCH -), 1.32 (t, 3H, -OCH CH ).
᎐
2
2
2
3
(m, 5H, ArH), 5.5 (m, 1H, CH ᎐CHCH -), 5.05 (t, 2H,
᎐
2
2
Acknowledgement
CH ᎐CHCH -), 4.66 (s, 1H, CCHCl), 3.97 (m, 3H, -OCH CH
᎐
2
2
2
3
and -OH), 2.85 (dd, J = 6.9, 13.9 Hz, 1H, CH ᎐CHCH -), 2.7
This work is financially supported by the Korean Ministry of
Science and Technology (Critical Technology-21) and the
Center for Molecular Design and Synthesis (CMDS), KAIST.
᎐
2
2
(dd, J = 7.4, 13.9 Hz, 1H, CH ᎐CHCH -), 0.95 (t, J = 7.14, 3H,
᎐
2
2
-OCH2CH3).
Preparation of allylic epoxides. General procedure
References
Method A. The chlorohydrin (from bromide A and entry 1 in
Table 1, 100 mg, 0.5 mmol), DBU (224 µL, 1.5 mmol) in THF
were stirred at room temperature for 14 h. The reaction mixture
was extracted with CH2Cl2 and washed 1 M HCl. The organic
layer was dried and concentrated to give the epoxide (66 mg,
81%). δH(300 MHz; CDCl3) 7.35 (m, 5H, ArH), 5.8 (m, 1H,
1 J. March, Advanced Organic Chemistry, 4th edn; John Wiley & Sons,
New York, 1992, pp. 434–435, 814–815.
2 (a) S. Araki, T. Hirashisa, H. Shimizu, H. Yamamura, M. Kawai
and Y. Butsugan, Tetrahedron Lett., 1996, 37, 8417; (b) T. H. Chan,
C. J. Li, M. C. Lee and Z. Y. Wei, Can. J. Chem., 1994, 72, 1181.
3 For a review, see: A. J. Fry, Comprehensive Organic Synthesis,
vol. 8, ed. I. Fleming, Pergamon Press, Oxford, 1991, pp. 983–997;
R. Noyori and Y. Hayakawa, Org. React., 1983, 29, 163; A. G.
Sutherland, Comprehensive Organic Functional Group Transform-
ations, vol. 1, ed. S. M. Roberts, Pergamon Press, Oxford, 1995,
pp. 1–11.
CH ᎐CHCH -), 3.01 (d, J = 5.1 Hz, 1H, -CH OC), 2.9 (dd,
᎐
2
2
J = 27.1, 15.0 Hz, 1H, CH ᎐CHCH -), 2.78 (d, J = 5.3 Hz, 1H,
᎐
2
2
-CH OC), 2.65 (dd, J = 7.6, 14.9 Hz, 1H, CH ᎐CHCH -).
᎐
2
2
2
4 R. Yanada, K. Bessho and K. Yanada, Chem. Lett., 1994, 1279;
A. D. Hughes and N. S. Simpkins, Synlett, 1998, 967; B. C. Ranu,
S. K. Guchhait and A. Sarkar, Chem. Commun., 1998, 2113; Y. Han
and Y. Z. Huang, Tetrahedron Lett., 1998, 39, 7751.
5 B. C. Ranu and U. Jana, J. Org. Chem., 1998, 63, 8212 and references
cited therein.
Method B. The chlorohydrin (from bromide A and entry 2 in
Table 1, 93 mg, 0.44 mmol) was dissolved in DMF and NaH
(80% dispersion in mineral oil, 40 mg, 1.32 mmol) was added.
The resulting solution was stirred at room temperature for 4 h,
then it was quenched with sat. NH4Cl. Ethyl acetate was added
948
J. Chem. Soc., Perkin Trans. 1, 2001, 946–948