492
R. P. C. Cousins et al. / Tetrahedron Letters 43 (2002) 489–492
(d) Seeberger, P. H.; Bilodeau, M. T.; Danishefsky, S. J.
Aldrichim. Acta 1997, 30, 75–92; (e) Davis, B. G. J.
Chem. Soc., Perkin Trans. 1 2000, 2137–2160.
ing a solvent modification [H2O–HOAc–CH2Cl2–MeCN
(1:2:4:5)].
8. Cotton, F. A.; Wilkinson, G.; Gaus, P. L. Basic Inorganic
Chemistry, 3rd ed.; Wiley: New York, 1995; p. 267 and
616.
9. Earlier, we had encountered a similar phenomenon in
hetero Diels–Alder reactions of (E)-1-methoxy-3-tert-
butyldimethylsiloxy-1,3-butadiene with 2-(2,3,4,6-tetra-
2. For examples involving achiral aldehydes, see: (a) Dan-
ishefsky, S.; Kerwin, J. F., Jr.; Kobayashi, S. J. Am.
Chem. Soc. 1982, 104, 358–360; (b) Aben, R. W.;
Scheeren, H. W. Synthesis 1982, 779–781; (c) Larson, E.
R.; Danishefsky, S. J. Am. Chem. Soc. 1983, 105, 6715–
6716; (d) Danishefsky, S.; Webb, R. R., II J. Org. Chem.
1984, 49, 1955–1958; (e) Danishefsky, S. J.; Maring, C. J.
J. Am. Chem. Soc. 1985, 107, 1269–1274; (f) Danishefsky,
S. J.; Larson, E.; Springer, J. P. J. Am. Chem. Soc. 1985,
107, 1274–1280; (g) Danishefsky, S.; Maring, C. J. Am.
Chem. Soc. 1985, 107, 7762–7764.
O-acetyl-b-
D
-glucopyranosyloxy)benzaldehyde.
See:
Cousins, R. P. C.; Ding, W. C.; Pritchard, R. G.; Stood-
ley, R. J. Chem. Commun. 1997, 2171–2172.
10. We have shown that related cycloadducts (cf. Ref. 4)
adopt a half-chair conformation with an equatorial dis-
position of the C(2) aryl group. Accordingly, the C(6)
oxy group is pseudo-equatorial when a syn-relationship
exists between the C(2) and C(6) substituents and pseudo-
axial for anti-cycloadducts. Typically, the coupling con-
stant between the C(5) and C(6) hydrogen atoms is 51.5
Hz for syn-cycloadducts and ꢀ3.5 Hz for anti-cycload-
ducts. In cycloadducts 5a and 6a, there was no discernible
coupling between the C(5) and C(6) hydrogen atoms.
11. Luche, J.-L. J. Am. Chem. Soc. 1978, 100, 2226–2227.
12. Crystal data for compound 10a: C25H29NO14, M=567.5,
monoclinic, space group P21, a=10.0292(10), b=
3. David has used the hetero Diels–Alder reaction of non-
anomerically linked sugar dienes and glyoxylates/oxoma-
lonates to construct (13)- and (14)-linked
disaccharides. See: David, S.; Eustache, J. J. Chem. Soc.,
Perkin Trans. 1 1979, 2521–2525 and references cited
therein.
4. We have shown that the diene 2 (R1=Ac, R2=But,
R3=2,3,4,6-tetra-O-acetyl-b-
D-glucopyranosyl) and a rel-
ative lacking the OAc substituent undergo endo-selective
cycloadditions with electron-deficient aryl/heteroaryl
aldehydes in the presence of Eu(fod)3, preferentially to
their Re-faces. See: (a) Lowe, R. F.; Stoodley, R. J.
Tetrahedron Lett. 1994, 35, 6351–6355; (b) Helliwell, M.;
Phillips, I. M.; Pritchard, R. G.; Stoodley, R. J. Tetra-
hedron Lett. 1999, 40, 8651–8655. The cycloadducts may
be regarded as (11)-linked disaccharide prototypes.
5. The high regio- and stereoselectivity associated with such
reductions, involving related systems, was first noted by
Danishefsky. See: Ref. 2c.
,
11.805(2), c=12.172(2) A, i=110.49(2)°, Dcalcd=1.396 g
3
−1
cm−3, V=1349.9(3) A , Z=2, v(Mo Ka)=0.116 mm
,
,
F(000)=596, T=203(2) K. Nonius MACH3 diffractome-
ter, crystal size 0.40×0.30×0.15 mm, qmax=25.0°, 2630
reflections measured, 2495 unique. Structure solution by
direct methods, full-matrix least-squares refinement
(SHELXL-97) on F2 with all non-hydrogen atoms
anisotropic and hydrogen atoms constrained in calculated
positions. The final cycle converged to R=0.0408 [for
reflections I>2|(I)] and wR2=0.1008 (for all reflections).
Crystallographic data (excluding structure factors) have
been deposited with the Cambridge Crystallographic
Data Centre as supplementary publication no. CCDC
167438.
6. Aben, R. W.; Scheeren, H. W. J. Chem. Soc., Perkin
Trans. 1 1979, 3132–3138.
7. This compound {mp 132–133°C, [h]2D0 −4 (c 0.5,
CH2Cl2)}, previously described as a syrup (Binder, W.
H.; Schmid, W. Monatsh. Chem. 1995, 126, 923–931) was
prepared (70% yield after crystallisation) by oxidative
13. Cotton, S. Lanthanides and Actinides; MacMillan: Lon-
don, 1991; p. 58.
14. Roberson, M.; Jepsen, A. S.; Jørgensen, K. A. Tetra-
hedron 2001, 57, 907–913.
cleavage of allyl 2,3,4,6-tetra-O-acetyl-b-D-glucopyrano-
side using RuO4 generated by the Sharpless method
(Carlsen, P. H. J.; Katsuki, T.; Martin, V. S.; Sharpless,
K. B. J. Org. Chem. 1981, 46, 3936–3938) but incorporat-