264
I. Hladezuk et al. / Carbohydrate Research 330 (2001) 257–265
cury(II) trifluoroacetate (0.1 equiv/8), only ke-
tone 14 was isolated in 83% yield.
3 h. Acetone was evaporated under reduced
pressure and the aq layer was diluted with 10
mL of water, the resulting mixture was ex-
tracted three times with CH2Cl2 (10 mL). The
combined organic layers were washed with
water, dried over anhyd magnesium sulfate
and evaporated under reduced pressure. The
residue was purified by chromatography (7/3:
EtOAc–heptane). Ketone 12 was eluted first
(0.14 g, 41%); [h]D −3.0° (c 1.05, CHCl3);
m/z (CI) 438–440 [M+H]+. Anal. Calcd for
C25H24ClNO4: C, 68.57; H, 5.52; N, 3.20.
Found: C, 68.55; H, 5.44; N, 3.55. Ketone 13
was then eluted (0.14 g 41%); [h]D −36.3° (c
1.07, CHCl3); m/z (CI) 438–440 [M+H]+.
Anal. Calcd for C25H24ClNO4: C, 68.57; H,
5.52; N, 3.20; Cl, 8.10. Found: C, 68.50; H,
5.67; N, 3.34; Cl, 8.02.
Method B: with mercury(II) trifluoroacetate.
With mercury(II) trifluoroacetate (1.2 equiv/
9), instead of mercury(II) chloride, as de-
scribed above, ketones 12 and 13 were isolated
in 37 and 37% yields, respectively.
Method C: catalytic method. With mer-
cury(II) trifluoroacetate (0.1 equiv/9), the ke-
tones 12 and 13 were isolated in 7 and 61%
yields, respectively.
2 - - (2,3,5/0) - 2,3 - dibenzyloxy - 3 - C - [(2%-
L
chloro)-pyrid-5%-yl]-5-hydroxycyclohexanone
-(2,3/5)-2,3-dibenzyloxy-3-C-[(2%-
(16) and 2-
L
chloro)-pyrid-5%-yl]-5-hydroxy-cyclohexanone
(17)
Method A: with mercury(II) trifluoroacetate.
With mercury(II) trifluoroacetate (1.2 equiv/
10), following the same procedure, chro-
matography (7/3: EtOAc–heptane) afforded
first ketone 16 (37%). [h]D −26.4° (c 1.10 in
CHCl3); m/z (CI) 438–440 [M+H]+, 330–
332 [M+H−PhCH2OH]+. Anal. Calcd for
C25H24ClNO4: C, 68.57; H, 5.52; N, 3.20; Cl,
8.10. Found: C, 68.46; H, 5.77; N, 3.06; Cl,
7.66. Ketone 17 was eluted next (37%); [h]D
−38.9° (c 1.08, CHCl3); m/z (CI) 438–440
[M+H]+, 330–332 [M+H−PhCH2OH]+.
Anal. Calcd for C25H24ClNO4: C, 68.57; H,
5.52; N, 3.20; Cl, 8.10. Found: C, 68.82; H,
5.31; N, 3.14; Cl, 8.38.
Method B: catalytic method. With mer-
cury(II) trifluoroacetate (0.1 equiv/10), the ke-
tones 16 and 17 were isolated in 23 and 54%
yields, respectively.
2-
pyrid-5%-yl]-3,5-dihydroxy-cyclohexanone (14)
and 2- -(2,3/5)-2-benzyloxy-3-C-[(2%-chloro)-
L
-(2,3,5/0)-2-benzyloxy-3-C-[(2%-chloro)-
2. Supplementary material
Complete crystallographic data (excluding
structure factors) for the structure reported in
this paper has been deposited at the Cam-
bridge Crystallographic Data Centre with no.
143894 CCDC. Copies of the data can be
obtained free of charge on application to The
Director, CCDC, 12 Union Road, Cambridge
CB2 1EZ, UK (fax: +44-1223-336033; e-
mail: deposit@ccdc.cam.ac.uk or, www: http:/
/www.ccdc.cam.ac.uk).
L
pyrid-5%-yl]-3,5-dihydro-xycyclohexanone (15)
Method A: with mercury(II) chloride. With
mercury(II) chloride (1.2 equiv/8), as de-
scribed above, chromatography (7/3: EtOAc–
heptane) afforded first ketone 14 (41%); [h]D
−59.3° (c 1.24, CHCl3); m/z (CI) 348–350
[M+H]+. Anal. Calcd for C18H18ClNO4: C,
62.16; H, 5.22; N, 4.03; Cl, 10.19. Found: C,
62.26; H, 5.05; N, 4.11; Cl, 10.14. Ketone 15
was eluted next (0.16 g, 48%); [h]D −65.2° (c
1.01, CHCl3); m/z (CI) 348–350 [M+H]+.
Anal. Calcd for C18H18ClNO4: C, 62.16; H,
5.22; N, 4.03; Cl, 10.19. Found: C, 62.18; H,
5.18; N, 3.98; Cl, 10.47.
References
1. (a) Broka, C. A. Tetrahedron Lett. 1993, 34, 3251–3254.
(b) Corey, E. J.; Loh, T. P.; Achyutharao, S.; Daley, D.
C.; Sarshar, S. J. Org. Chem. 1993, 58, 5600–5602. (c)
Fletcher, S. R.; Baker, R.; Chambers, M. S.; Hobbs, S.
C.; Mitchell, P. J. J. Chem. Soc., Chem. Commun. 1993,
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Method B: with mercury(II) trifluoroacetate.
With mercury(II) trifluoroacetate (1.2 equiv/
8), instead of mercury(II) chloride, the ketones
14 and 15 were isolated in 78 and 9% yields,
respectively.
Method C: catalytic method. With mer-