P. Ciuffreda et al. / Tetrahedron: Asymmetry 13 (2002) 239–241
241
Acknowledgements
(1H, dd, J=4.7, 12.0 Hz, H-5%b), 1.59 (3H, s, CCH3),
1.36 (3H, s, CCH3).
10. Ranganathan, R. S.; Jones, G. H.; Moffatt, J. G. J. Org.
Chem. 1974, 39, 290–297.
This work has been financially supported by Universita`
degli Studi di Milano (Fondi ex 60%) and the Italian
National Council for Research (CNR, Target Project in
Biotechnology).
11. Major diastereomer: HPLC tr=10.9 (phosphate buffer
1
pH 6.0/CH3CN, 8:2); H NMR (CD3OD) l 8.29 (1H, s,
H-2), 8.18 (1H, s, H-8), 6.11 (1H, d, J=3.4 Hz, H-1%),
5.21 (1H, dd, J=3.4, 6.0 Hz, H-2%), 5.07 (1H, dd, J=2.7,
6.0 Hz, H-3%), 4.12 (1H, dd, J=2.7, 3.4 Hz, H-4%), 3.97
(1H, dq, J=3.4, 6.0 Hz, H-5%), 1.61 (3H, s, CCH3), 1.38
(3H, s, CCH3), 1.19 (3H, d, J=6.0 Hz, CH3). Minor
diastereomer: HPLC tr=10.2 (phosphate buffer pH 6.0/
CH3CN, 8:2); l 8.36 (1H, s, H-2), 8.19 (1H, s, H-8), 6.15
(1H, d, J=3.4 Hz, H-1%), 5.18 (1H, dd, J=3.4, 6.0 Hz,
H-2%), 4.98 (1H, dd, J=2.7, 6.0 Hz, H-3%), 4.16 (1H, dd,
J=2.7, 3.4 Hz, H-4%), 3.93 (1H, dq, J=3.4, 6.0 Hz, H-5%),
1.59 (3H, s, CCH3), 1.36 (3H, s, CCH3), 1.21 (3H, d,
J=6.0 Hz, CH3).
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1
[h]2D5 −35.4 (c 1, MeOH); H NMR (CD3OD) l 8.38 (1H,
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dd, J=2.7, 6.7 Hz, H-3%), 4.34 (1H, ddd, J=2.7, 4.0, 4.7
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